diff --git a/examples/al-easy-access-simbad-ned.html b/examples/al-easy-access-simbad-ned.html
index 4803f250..6fe95f7e 100644
--- a/examples/al-easy-access-simbad-ned.html
+++ b/examples/al-easy-access-simbad-ned.html
@@ -20,6 +20,7 @@
         showSettingsControl: true,
         showStackLayerControl: true,
         samp: true,
+        showCooGrid: true,
       });
 
       aladin.addCatalog(A.catalogFromSimbad('M 82', 0.1, {onClick: 'showTable'}));
diff --git a/src/core/al-api/src/angle_fmt.rs b/src/core/al-api/src/angle.rs
similarity index 60%
rename from src/core/al-api/src/angle_fmt.rs
rename to src/core/al-api/src/angle.rs
index 49ff3e97..cf1d410b 100644
--- a/src/core/al-api/src/angle_fmt.rs
+++ b/src/core/al-api/src/angle.rs
@@ -1,8 +1,6 @@
 use serde::{Deserialize, Serialize};
 use wasm_bindgen::prelude::*;
 
-use std::fmt;
-
 #[wasm_bindgen(raw_module = "../../js/libs/astro/coo.js")]
 extern "C" {
     #[wasm_bindgen(js_name = Format)]
@@ -28,28 +26,11 @@ extern "C" {
     pub fn toDecimal(num: f64, prec: u8) -> String;
 }
 
-#[derive(Deserialize, Serialize, Debug, Clone, Copy, PartialEq)]
+use std::cmp::Eq;
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[serde(rename_all = "camelCase")]
 #[wasm_bindgen]
-pub enum AngleSerializeFmt {
-    DMM,
-    DD,
-    DMS,
-    HMS,
-}
-
-impl fmt::Display for AngleSerializeFmt {
-    // This trait requires `fmt` with this exact signature.
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        // Write strictly the first element into the supplied output
-        // stream: `f`. Returns `fmt::Result` which indicates whether the
-        // operation succeeded or failed. Note that `write!` uses syntax which
-        // is very similar to `println!`.
-        let str = match self {
-            Self::DMM => "DMM",
-            Self::DD => "DD",
-            Self::DMS => "DMS",
-            Self::HMS => "HMS",
-        };
-        write!(f, "{}", str)
-    }
-}
+pub enum Formatter {
+    Sexagesimal,
+    Decimal
+}
\ No newline at end of file
diff --git a/src/core/al-api/src/grid.rs b/src/core/al-api/src/grid.rs
index 41b65f6e..f87a0c4d 100644
--- a/src/core/al-api/src/grid.rs
+++ b/src/core/al-api/src/grid.rs
@@ -1,12 +1,9 @@
-use wasm_bindgen::prelude::*;
-
 use serde::{Deserialize, Serialize};
 
-use crate::angle_fmt::AngleSerializeFmt;
+use crate::angle::Formatter;
 
 use super::color::ColorRGB;
 
-#[wasm_bindgen]
 #[derive(Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct GridCfg {
@@ -22,7 +19,7 @@ pub struct GridCfg {
     #[serde(default = "default_enabled")]
     pub enabled: Option<bool>,
     #[serde(default = "default_fmt")]
-    pub fmt: Option<AngleSerializeFmt>,
+    pub fmt: Option<Formatter>,
 }
 
 fn default_labels() -> Option<bool> {
@@ -45,6 +42,6 @@ fn default_thickness() -> Option<f32> {
     None
 }
 
-fn default_fmt() -> Option<AngleSerializeFmt> {
+fn default_fmt() -> Option<Formatter> {
     None
 }
diff --git a/src/core/al-api/src/lib.rs b/src/core/al-api/src/lib.rs
index 0c254307..7962bcae 100644
--- a/src/core/al-api/src/lib.rs
+++ b/src/core/al-api/src/lib.rs
@@ -13,7 +13,7 @@ pub mod resources;
 pub mod cell;
 pub mod fov;
 pub mod image;
-pub mod angle_fmt;
+pub mod angle;
 
 pub trait Abort {
     type Item;
diff --git a/src/core/src/app.rs b/src/core/src/app.rs
index baa1284a..8ed59439 100644
--- a/src/core/src/app.rs
+++ b/src/core/src/app.rs
@@ -20,6 +20,7 @@ use crate::{
     tile_fetcher::TileFetcherQueue,
     time::DeltaTime,
 };
+use crate::math::angle::ToAngle;
 use al_core::image::format::ChannelType;
 use wcs::WCS;
 
@@ -421,7 +422,7 @@ impl App {
                 let v = cell.vertices();
                 let proj2screen = |(lon, lat): &(f64, f64)| -> Option<[f64; 2]> {
                     // 1. convert to xyzw
-                    let xyzw = crate::math::lonlat::radec_to_xyzw(Angle(*lon), Angle(*lat));
+                    let xyzw = crate::math::lonlat::radec_to_xyzw(lon.to_angle(), lat.to_angle());
                     // 2. get it back to the camera frame system
                     let xyzw = crate::coosys::apply_coo_system(
                         CooSystem::ICRS,
@@ -1325,7 +1326,7 @@ impl App {
         Ok(())
     }
 
-    pub(crate) fn get_max_fov(&self) -> f64 {
+    pub(crate) fn get_max_fov(&self) -> Angle<f64> {
         self.projection.aperture_start()
     }
 
diff --git a/src/core/src/camera/mod.rs b/src/core/src/camera/mod.rs
index cc37623c..f04af27e 100644
--- a/src/core/src/camera/mod.rs
+++ b/src/core/src/camera/mod.rs
@@ -41,7 +41,7 @@ pub fn build_fov_coverage(
 
             let hpx_idxs_iter = vertices_iter.map(|v| {
                 let (lon, lat) = crate::math::lonlat::xyzw_to_radec(&v);
-                ::healpix::nested::hash(depth, lon.0, lat.0)
+                ::healpix::nested::hash(depth, lon.to_radians(), lat.to_radians())
             });
 
             HEALPixCoverage::from_fixed_hpx_cells(depth, hpx_idxs_iter, Some(vertices.len()))
diff --git a/src/core/src/camera/viewport.rs b/src/core/src/camera/viewport.rs
index 2d74e5a2..e4db7baa 100644
--- a/src/core/src/camera/viewport.rs
+++ b/src/core/src/camera/viewport.rs
@@ -88,7 +88,6 @@ const MAX_DPI_LIMIT: f32 = 2.0;
 use crate::math;
 use crate::time::Time;
 use crate::Abort;
-use crate::ArcDeg;
 impl CameraViewPort {
     pub fn new(
         gl: &WebGlContext,
@@ -97,7 +96,7 @@ impl CameraViewPort {
     ) -> CameraViewPort {
         let last_user_action = UserAction::Starting;
 
-        let aperture = Angle(projection.aperture_start());
+        let aperture = projection.aperture_start();
 
         let w2m = Matrix4::identity();
         let m2w = w2m;
@@ -350,12 +349,12 @@ impl CameraViewPort {
             _ => true,
         };
 
-        let aperture_start: Angle<f64> = ArcDeg(proj.aperture_start()).into();
+        let aperture_start = proj.aperture_start();
 
         self.clip_zoom_factor = if aperture > aperture_start {
             //al_core::log(&format!("a: {:?}, as: {:?}", aperture, aperture_start));
             if can_unzoom_more {
-                aperture.0 / aperture_start.0
+                aperture.to_radians() / aperture_start.to_radians()
             } else {
                 1.0
             }
@@ -363,8 +362,8 @@ impl CameraViewPort {
             // Compute the new clip zoom factor
             let a = aperture.abs();
 
-            let v0 = math::lonlat::radec_to_xyzw(-a / 2.0, Angle(0.0));
-            let v1 = math::lonlat::radec_to_xyzw(a / 2.0, Angle(0.0));
+            let v0 = math::lonlat::radec_to_xyzw(-a / 2.0, 0.0.to_angle());
+            let v1 = math::lonlat::radec_to_xyzw(a / 2.0, 0.0.to_angle());
 
             // Vertex in the WCS of the FOV
             if self.width < self.height {
diff --git a/src/core/src/coosys.rs b/src/core/src/coosys.rs
index 34f4a023..371d158d 100644
--- a/src/core/src/coosys.rs
+++ b/src/core/src/coosys.rs
@@ -39,8 +39,8 @@ mod tests {
         let gal_lonlat =
             super::apply_coo_system(CooSystem::ICRS, CooSystem::GAL, &lonlat.vector()).lonlat();
 
-        let gal_lon_deg = gal_lonlat.lon().0 * 360.0 / (2.0 * std::f64::consts::PI);
-        let gal_lat_deg = gal_lonlat.lat().0 * 360.0 / (2.0 * std::f64::consts::PI);
+        let gal_lon_deg = gal_lonlat.lon().to_degrees();
+        let gal_lat_deg = gal_lonlat.lat().to_degrees();
 
         assert_delta!(gal_lon_deg, 96.33723581, 1e-3);
         assert_delta!(gal_lat_deg, -60.18845577, 1e-3);
@@ -56,8 +56,8 @@ mod tests {
         let lonlat: LonLatT<f64> = LonLatT::new(ArcDeg(0.0).into(), ArcDeg(0.0).into());
         let j2000_lonlat =
             super::apply_coo_system(CooSystem::GAL, CooSystem::ICRS, &lonlat.vector()).lonlat();
-        let j2000_lon_deg = j2000_lonlat.lon().0 * 360.0 / (2.0 * std::f64::consts::PI);
-        let j2000_lat_deg = j2000_lonlat.lat().0 * 360.0 / (2.0 * std::f64::consts::PI);
+        let j2000_lon_deg = j2000_lonlat.lon().to_degrees();
+        let j2000_lat_deg = j2000_lonlat.lat().to_degrees();
 
         assert_delta!(j2000_lon_deg, 266.40506655, 1e-3);
         assert_delta!(j2000_lat_deg, -28.93616241, 1e-3);
@@ -77,8 +77,8 @@ mod tests {
 
         let gal_lonlat = super::apply_coo_system(CooSystem::ICRS, CooSystem::GAL, &icrs_pos);
 
-        let gal_lon_deg = gal_lonlat.lon().0 * 360.0 / (2.0 * std::f64::consts::PI);
-        let gal_lat_deg = gal_lonlat.lat().0 * 360.0 / (2.0 * std::f64::consts::PI);
+        let gal_lon_deg = gal_lonlat.lon().to_degrees();
+        let gal_lat_deg = gal_lonlat.lat().to_degrees();
 
         assert_delta!(gal_lon_deg, 0.0, 1e-3);
         assert_delta!(gal_lat_deg, 0.0, 1e-3);
diff --git a/src/core/src/healpix/coverage.rs b/src/core/src/healpix/coverage.rs
index ef0ffb0e..a4002c66 100644
--- a/src/core/src/healpix/coverage.rs
+++ b/src/core/src/healpix/coverage.rs
@@ -27,15 +27,14 @@ impl HEALPixCoverage {
         let lonlat = vertices_iter
             .map(|vertex| {
                 let LonLatT(lon, lat) = vertex.lonlat();
-                //let (lon, lat) = math::lonlat::xyzw_to_radec(&vertex);
-                (lon.0, lat.0)
+                (lon.to_radians(), lat.to_radians())
             })
             .collect::<Vec<_>>();
 
         let LonLatT(in_lon, in_lat) = inside.lonlat();
         let moc = RangeMOC::from_polygon_with_control_point(
             &lonlat[..],
-            (in_lon.0, in_lat.0),
+            (in_lon.to_radians(), in_lat.to_radians()),
             depth,
             CellSelection::All,
         );
@@ -84,11 +83,11 @@ impl HEALPixCoverage {
 
     pub fn contains_coo(&self, coo: &Vector4<f64>) -> bool {
         let (lon, lat) = math::lonlat::xyzw_to_radec(coo);
-        self.0.is_in(lon.0, lat.0)
+        self.0.is_in(lon.to_radians(), lat.to_radians())
     }
 
     pub fn contains_lonlat(&self, lonlat: &LonLatT<f64>) -> bool {
-        self.0.is_in(lonlat.lon().0, lonlat.lat().0)
+        self.0.is_in(lonlat.lon().to_radians(), lonlat.lat().to_radians())
     }
 
     // O(log2(N))
diff --git a/src/core/src/healpix/utils.rs b/src/core/src/healpix/utils.rs
index 080acfd8..a5ca2a21 100644
--- a/src/core/src/healpix/utils.rs
+++ b/src/core/src/healpix/utils.rs
@@ -1,5 +1,6 @@
 use crate::healpix::cell::HEALPixCell;
-use crate::math::{angle::Angle, lonlat::LonLatT};
+use crate::math::lonlat::LonLatT;
+use crate::math::angle::ToAngle;
 /// A simple wrapper around sore core methods
 /// of cdshealpix
 ///
@@ -17,15 +18,15 @@ pub fn vertices_lonlat<S: BaseFloat>(cell: &HEALPixCell) -> [LonLatT<S>; 4] {
             let lon = S::from(*lon).unwrap_abort();
             let lat = S::from(*lat).unwrap_abort();
 
-            (lon, lat)
+            (lon.to_angle(), lat.to_angle())
         })
         .unzip();
 
     [
-        LonLatT::new(Angle(lon[0]), Angle(lat[0])),
-        LonLatT::new(Angle(lon[1]), Angle(lat[1])),
-        LonLatT::new(Angle(lon[2]), Angle(lat[2])),
-        LonLatT::new(Angle(lon[3]), Angle(lat[3])),
+        LonLatT::new(lon[0], lat[0]),
+        LonLatT::new(lon[1], lat[1]),
+        LonLatT::new(lon[2], lat[2]),
+        LonLatT::new(lon[3], lat[3]),
     ]
 }
 use crate::Abort;
@@ -40,13 +41,13 @@ pub fn grid_lonlat<S: BaseFloat>(cell: &HEALPixCell, n_segments_by_side: u16) ->
             let lon = S::from(*lon).unwrap_abort();
             let lat = S::from(*lat).unwrap_abort();
 
-            LonLatT::new(Angle(lon), Angle(lat))
+            LonLatT::new(lon.to_angle(), lat.to_angle())
         })
         .collect()
 }
 
 pub fn hash_with_dxdy(depth: u8, lonlat: &LonLatT<f64>) -> (u64, f64, f64) {
-    healpix::nested::hash_with_dxdy(depth, lonlat.lon().0, lonlat.lat().0)
+    healpix::nested::hash_with_dxdy(depth, lonlat.lon().to_radians(), lonlat.lat().to_radians())
 }
 
 pub const MEAN_HPX_CELL_RES: &[f64; 30] = &[
diff --git a/src/core/src/lib.rs b/src/core/src/lib.rs
index fa85fd99..38309b62 100644
--- a/src/core/src/lib.rs
+++ b/src/core/src/lib.rs
@@ -562,7 +562,7 @@ impl WebClient {
     /// the sinus would be 180 degrees.
     #[wasm_bindgen(js_name = getMaxFieldOfView)]
     pub fn get_max_fov(&mut self) -> f64 {
-        self.app.get_max_fov()
+        self.app.get_max_fov().to_degrees()
     }
 
     /// Get the clip zoom factor of the view
diff --git a/src/core/src/math/angle.rs b/src/core/src/math/angle.rs
index f7ecc660..ae893e77 100644
--- a/src/core/src/math/angle.rs
+++ b/src/core/src/math/angle.rs
@@ -1,4 +1,5 @@
 use cgmath::BaseFloat;
+use crate::Abort;
 // ArcDeg wrapper structure
 #[derive(Clone, Copy)]
 pub struct ArcDeg<T: BaseFloat>(pub T);
@@ -6,23 +7,6 @@ pub struct ArcDeg<T: BaseFloat>(pub T);
 //pub const TWICE_PI: f64 = 6.28318530718;
 pub const PI: f64 = std::f64::consts::PI;
 
-impl<T> ArcDeg<T>
-where
-    T: BaseFloat,
-{
-    fn get_frac_minutes(&self) -> ArcMin<T> {
-        let deg = *self;
-
-        let frac = deg.fract();
-        let minutes_per_degree = T::from(60_f32).unwrap_abort();
-        ArcMin(frac * minutes_per_degree)
-    }
-
-    fn truncate(&mut self) {
-        *self = Self((*self).trunc());
-    }
-}
-
 use cgmath::{Deg, Rad};
 use serde::Deserialize;
 // Convert a Rad<T> to an ArcDeg<T>
@@ -71,18 +55,6 @@ where
 #[derive(Clone, Copy)]
 pub struct ArcHour<T: BaseFloat>(pub T);
 
-impl<T> ArcHour<T>
-where
-    T: BaseFloat,
-{
-    fn get_frac_minutes(&self) -> ArcMin<T> {
-        let hour = *self;
-
-        let frac = hour.fract();
-        let minutes_per_hour = T::from(60_f64).unwrap_abort();
-        ArcMin(minutes_per_hour * frac)
-    }
-}
 
 impl<T> From<Rad<T>> for ArcHour<T>
 where
@@ -122,19 +94,6 @@ where
 #[derive(Clone, Copy)]
 pub struct ArcMin<T: BaseFloat>(pub T);
 
-impl<T> ArcMin<T>
-where
-    T: BaseFloat,
-{
-    fn get_frac_seconds(&self) -> ArcSec<T> {
-        let min: ArcMin<T> = *self;
-
-        let frac = min.fract();
-        let seconds_per_min = T::from(60_f64).unwrap_abort();
-        ArcSec(seconds_per_min * frac)
-    }
-}
-
 // Convert a Rad<T> to an ArcMin<T>
 impl<T> From<Rad<T>> for ArcMin<T>
 where
@@ -241,6 +200,8 @@ where
     }
 }
 
+use al_api::angle::Format;
+/*
 pub enum SerializeFmt {
     DMS,
     HMS,
@@ -269,7 +230,7 @@ impl SerializeFmt {
             Self::DD => DD::to_string(angle),
         }
     }
-}
+}*/
 
 /*pub trait SerializeToString {
     fn to_string(&self) -> String;
@@ -284,6 +245,7 @@ where
     }
 }*/
 
+/*
 pub struct DMS;
 pub struct HMS;
 pub struct DMM;
@@ -315,7 +277,7 @@ impl FormatType for DMM {
         result
     }
 }
-use crate::Abort;
+
 impl FormatType for DMS {
     fn to_string<S: BaseFloat + ToString>(angle: Angle<S>) -> String {
         let angle = Rad(angle.0);
@@ -361,94 +323,106 @@ impl FormatType for HMS {
 
         result
     }
-}
+}*/
+
 
 #[derive(Clone, Copy, Debug, Eq, Hash, Deserialize)]
 #[serde(rename_all = "camelCase")]
 #[repr(C)]
-pub struct Angle<S: BaseFloat>(pub S);
+pub struct Angle<S: BaseFloat> {
+    pub rad: S,
+    fmt: AngleFormatter,
+}
 impl<S> Angle<S>
 where
     S: BaseFloat,
 {
     pub fn new<T: Into<Rad<S>>>(angle: T) -> Angle<S> {
         let radians: Rad<S> = angle.into();
-        Angle(radians.0)
+        Angle { rad: radians.0, fmt: AngleFormatter::default() }
     }
 
     pub fn cos(&self) -> S {
-        self.0.cos()
+        self.rad.cos()
     }
 
     pub fn sin(&self) -> S {
-        self.0.sin()
+        self.rad.sin()
     }
 
     pub fn tan(&self) -> S {
-        self.0.tan()
+        self.rad.tan()
     }
 
     pub fn asin(self) -> S {
-        self.0.asin()
+        self.rad.asin()
     }
 
     pub fn acos(self) -> S {
-        self.0.acos()
+        self.rad.acos()
     }
 
     pub fn atan(self) -> S {
-        self.0.atan()
+        self.rad.atan()
     }
 
     pub fn atan2(self, other: Self) -> S {
-        self.0.atan2(other.0)
+        self.rad.atan2(other.rad)
     }
 
     pub fn floor(self) -> Self {
-        Angle(self.0.floor())
+        self.rad.floor().to_angle()
     }
 
     pub fn ceil(self) -> Self {
-        Angle(self.0.ceil())
+        self.rad.ceil().to_angle()
     }
 
     pub fn round(self) -> Self {
-        Angle(self.0.round())
+        self.rad.round().to_angle()
     }
 
     pub fn trunc(self) -> Self {
-        Angle(self.0.trunc())
+        self.rad.trunc().to_angle()
     }
 
     pub fn fract(self) -> S {
-        self.0.fract()
+        self.rad.fract()
     }
 
     pub fn abs(self) -> Self {
-        Angle(self.0.abs())
+        self.rad.abs().to_angle()
     }
 
     pub fn max(self, other: Self) -> Self {
-        Angle(self.0.max(other.0))
+        self.rad.max(other.rad).to_angle()
     }
 
     pub fn min(self, other: Self) -> Self {
-        Angle(self.0.min(other.0))
+        self.rad.min(other.rad).to_angle()
     }
 
     pub fn min_value() -> Self {
-        Angle(S::min_value())
+        S::min_value().to_angle()
     }
     pub fn max_value() -> Self {
-        Angle(S::max_value())
+        S::max_value().to_angle()
     }
 
     pub fn to_radians(&self) -> S {
-        self.0
+        self.rad
     }
 
     pub fn to_degrees(&self) -> S {
-        self.0.to_degrees()
+        self.rad.to_degrees()
+    }
+
+    pub fn to_hours(&self) -> S {
+        self.to_degrees() / S::from(15.0).unwrap()
+    }
+
+    pub fn set_format(&mut self, fmt: AngleFormatter) {
+        self.fmt = fmt;
     }
 }
 
@@ -464,7 +438,7 @@ where
     S: BaseFloat,
 {
     fn to_angle(self) -> Angle<S> {
-        Angle(self)
+        Angle { rad: self, fmt: Default::default() } 
     }
 }
 
@@ -474,7 +448,7 @@ where
     S: BaseFloat,
 {
     fn from(rad: Rad<S>) -> Self {
-        Angle(rad.0)
+        rad.0.to_angle()
     }
 }
 impl<S> From<Angle<S>> for Rad<S>
@@ -482,7 +456,7 @@ where
     S: BaseFloat,
 {
     fn from(angle: Angle<S>) -> Self {
-        Rad(angle.0)
+        Rad(angle.rad)
     }
 }
 
@@ -501,7 +475,7 @@ where
 {
     fn eq(&self, other: &T) -> bool {
         let angle: Angle<S> = (*other).into();
-        angle.0 == self.0
+        angle.rad == self.rad
     }
 }
 
@@ -513,7 +487,7 @@ where
 {
     fn partial_cmp(&self, other: &T) -> Option<Ordering> {
         let angle: Angle<S> = (*other).into();
-        self.0.partial_cmp(&angle.0)
+        self.rad.partial_cmp(&angle.rad)
     }
 }
 
@@ -524,7 +498,7 @@ where
 {
     fn from(deg: ArcDeg<S>) -> Self {
         let rad: Rad<S> = deg.into();
-        Angle(rad.0)
+        rad.0.to_angle()
     }
 }
 impl<S> From<Angle<S>> for ArcDeg<S>
@@ -545,7 +519,7 @@ where
 {
     fn from(min: ArcMin<S>) -> Self {
         let rad: Rad<S> = min.into();
-        Angle(rad.0)
+        rad.0.to_angle()
     }
 }
 // Convert from ArcSec<S>
@@ -555,28 +529,11 @@ where
 {
     fn from(sec: ArcSec<S>) -> Self {
         let rad: Rad<S> = sec.into();
-        Angle(rad.0)
+        rad.0.to_angle()
     }
 }
-/*
-impl<S> PartialEq<S> for Angle<S>
-where
-    S: BaseFloat + !AngleUnit<S>,
-{
-    fn eq(&self, other: &S) -> bool {
-        self.0 == *other
-    }
-}
-*/
+
 use std::cmp::Ordering;
-/*impl<S> PartialOrd<S> for Angle<S>
-where
-    S: BaseFloat,
-{
-    fn partial_cmp(&self, other: &S) -> Option<Ordering> {
-        self.0.partial_cmp(other)
-    }
-}*/
 
 use std::ops::Div;
 impl<S> Div for Angle<S>
@@ -586,8 +543,8 @@ where
     type Output = Self;
 
     fn div(self, rhs: Self) -> Self::Output {
-        let angle = self.0 / rhs.0;
-        Angle(angle)
+        let rad = self.rad / rhs.rad;
+        rad.to_angle()
     }
 }
 impl<S> Div<S> for Angle<S>
@@ -597,8 +554,8 @@ where
     type Output = Self;
 
     fn div(self, rhs: S) -> Self::Output {
-        let angle = self.0 / rhs;
-        Angle(angle)
+        let rad = self.rad / rhs;
+        rad.to_angle()
     }
 }
 
@@ -610,8 +567,8 @@ where
     type Output = Self;
 
     fn mul(self, rhs: Self) -> Self::Output {
-        let angle = self.0 * rhs.0;
-        Angle(angle)
+        let angle = self.rad * rhs.rad;
+        angle.to_angle()
     }
 }
 impl<S> Mul<S> for Angle<S>
@@ -621,8 +578,8 @@ where
     type Output = Self;
 
     fn mul(self, rhs: S) -> Self::Output {
-        let angle = self.0 * rhs;
-        Angle(angle)
+        let angle = self.rad * rhs;
+        angle.to_angle()
     }
 }
 
@@ -634,8 +591,8 @@ where
     type Output = Self;
 
     fn sub(self, other: Self) -> Self::Output {
-        let angle = self.0 - other.0;
-        Angle(angle)
+        let angle = self.rad - other.rad;
+        angle.to_angle()
     }
 }
 impl<S> Sub<S> for Angle<S>
@@ -645,8 +602,8 @@ where
     type Output = Self;
 
     fn sub(self, other: S) -> Self::Output {
-        let angle = self.0 - other;
-        Angle(angle)
+        let angle = self.rad - other;
+        angle.to_angle()
     }
 }
 
@@ -658,8 +615,8 @@ where
     type Output = Self;
 
     fn add(self, other: Self) -> Self::Output {
-        let angle = self.0 + other.0;
-        Angle(angle)
+        let angle = self.rad + other.rad;
+        angle.to_angle()
     }
 }
 impl<S> Add<S> for Angle<S>
@@ -669,8 +626,8 @@ where
     type Output = Self;
 
     fn add(self, other: S) -> Self::Output {
-        let angle = self.0 + other;
-        Angle(angle)
+        let angle = self.rad + other;
+        angle.to_angle()
     }
 }
 
@@ -718,8 +675,56 @@ where
     type Output = Self;
 
     fn rem(self, other: Self) -> Self::Output {
-        let angle = self.0 % other.0;
-        Angle(angle)
+        let angle = self.rad % other.rad;
+        angle.to_angle()
+    }
+}
+
+#[derive(PartialEq, Eq, Clone, Copy, Debug, Hash, Deserialize)]
+pub enum AngleFormatter {
+    Sexagesimal {
+        /// Number of digit of precision for the unit value
+        /// (interpreted as hours or degrees depending of the hours boolean field)
+        prec: u8,
+        /// Whether a '+' is added
+        plus: bool,
+        /// HMS or DMS
+        hours: bool,
+    },
+    Decimal {
+        /// Number of digit of precision
+        prec: u8,
+    }
+}
+
+impl Default for AngleFormatter {
+    fn default() -> Self {
+        AngleFormatter::Decimal { prec: 8 }
+    }
+}
+
+use std::fmt::Display;
+impl Display for Angle<f64> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.fmt {
+            AngleFormatter::Sexagesimal { prec, plus, hours } => {
+                let unit = if hours {
+                    self.to_hours()
+                } else {
+                    self.to_degrees()
+                };
+                // Round at a specific number of digit of precision
+                let pw = 10.0_f64.powi(prec as i32);
+                let unit = (unit * pw).round() / pw;
+
+                // Format the unit value to sexagesimal.
+                // The precision 8 corresponds to the formatting: deg/hour min sec.ddd
+                write!(f, "{}", Format::toSexagesimal(unit, 8, plus))
+            },
+            AngleFormatter::Decimal { prec } => {
+                write!(f, "{:.1$}°", self.to_degrees(), prec as usize)
+            }
+        }
     }
 }
 
@@ -730,18 +735,18 @@ where
 {
     type Output = Self;
     fn neg(self) -> Self::Output {
-        Angle(-self.0)
+        (-self.rad).to_angle()
     }
 }
 use al_core::{shader::UniformType, WebGlContext};
 use web_sys::WebGlUniformLocation;
 impl UniformType for Angle<f32> {
     fn uniform(gl: &WebGlContext, location: Option<&WebGlUniformLocation>, value: &Self) {
-        gl.uniform1f(location, value.0);
+        gl.uniform1f(location, value.rad);
     }
 }
 impl UniformType for Angle<f64> {
     fn uniform(gl: &WebGlContext, location: Option<&WebGlUniformLocation>, value: &Self) {
-        gl.uniform1f(location, value.0 as f32);
+        gl.uniform1f(location, value.rad as f32);
     }
 }
diff --git a/src/core/src/math/lonlat.rs b/src/core/src/math/lonlat.rs
index 5a2f6460..19f8b0ea 100644
--- a/src/core/src/math/lonlat.rs
+++ b/src/core/src/math/lonlat.rs
@@ -26,8 +26,8 @@ where
     /// * ``lon`` - Longitude
     /// * ``lat`` - Latitude
     pub fn new(mut lon: Angle<S>, lat: Angle<S>) -> LonLatT<S> {
-        if lon.0 < S::zero() {
-            lon.0 = lon.0 + S::from(TWICE_PI).unwrap_abort();
+        if lon.to_radians() < S::zero() {
+            lon = lon + S::from(TWICE_PI).unwrap_abort();
         }
 
         LonLatT(lon, lat)
@@ -156,33 +156,31 @@ where
 #[inline]
 pub fn ang_between_lonlat<S: BaseFloat>(lonlat1: LonLatT<S>, lonlat2: LonLatT<S>) -> Angle<S> {
     let abs_diff_lon = (lonlat1.lon() - lonlat2.lon()).abs();
-    Angle(
-        (lonlat1.lat().sin() * lonlat2.lat().sin()
-            + lonlat1.lat().cos() * lonlat2.lat().cos() * abs_diff_lon.cos())
-        .acos(),
-    )
+    (lonlat1.lat().sin() * lonlat2.lat().sin()
+        + lonlat1.lat().cos() * lonlat2.lat().cos() * abs_diff_lon.cos())
+    .acos().to_angle()
 }
 
 #[inline]
 pub fn xyz_to_radec<S: BaseFloat>(v: &Vector3<S>) -> (Angle<S>, Angle<S>) {
-    let lon = Angle(v.x.atan2(v.z));
-    let lat = Angle(v.y.atan2((v.x * v.x + v.z * v.z).sqrt()));
+    let lon = (v.x.atan2(v.z)).to_angle();
+    let lat = (v.y.atan2((v.x * v.x + v.z * v.z).sqrt())).to_angle();
 
     (lon, lat)
 }
 
 #[inline]
 pub fn xyzw_to_radec<S: BaseFloat>(v: &Vector4<S>) -> (Angle<S>, Angle<S>) {
-    let lon = Angle(v.x.atan2(v.z));
-    let lat = Angle(v.y.atan2((v.x * v.x + v.z * v.z).sqrt()));
+    let lon = (v.x.atan2(v.z)).to_angle();
+    let lat = (v.y.atan2((v.x * v.x + v.z * v.z).sqrt())).to_angle();
 
     (lon, lat)
 }
 
 #[inline]
 pub fn radec_to_xyz<S: BaseFloat>(theta: Angle<S>, delta: Angle<S>) -> Vector3<S> {
-    let (ds, dc) = delta.0.sin_cos();
-    let (ts, tc) = theta.0.sin_cos();
+    let (ds, dc) = delta.to_radians().sin_cos();
+    let (ts, tc) = theta.to_radians().sin_cos();
 
     Vector3::<S>::new(dc * ts, ds, dc * tc)
 }
diff --git a/src/core/src/math/projection/mod.rs b/src/core/src/math/projection/mod.rs
index a64eae80..143af311 100644
--- a/src/core/src/math/projection/mod.rs
+++ b/src/core/src/math/projection/mod.rs
@@ -19,8 +19,10 @@ use cgmath::Vector2;
 pub mod coo_space;
 pub mod domain;
 
-use domain::{basic, full::FullScreen};
+use crate::math::angle::ToAngle;
 
+use domain::{basic, full::FullScreen};
+use crate::math::angle::Angle;
 /* S <-> NDC space conversion methods */
 pub fn screen_to_ndc_space(
     pos_screen_space: &XYScreen<f64>,
@@ -304,7 +306,7 @@ impl ProjectionType {
         }
     }*/
 
-    pub fn bounds_size_ratio(&self) -> f64 {
+    pub const fn bounds_size_ratio(&self) -> f64 {
         match self {
             // Zenithal projections
             /* TAN,      Gnomonic projection        */
@@ -355,17 +357,17 @@ impl ProjectionType {
         }
     }
 
-    pub fn aperture_start(&self) -> f64 {
+    pub fn aperture_start(&self) -> Angle<f64> {
         match self {
             // Zenithal projections
             /* TAN,      Gnomonic projection        */
-            ProjectionType::Tan(_) => 150.0,
+            ProjectionType::Tan(_) => 150.0_f64.to_radians().to_angle(),
             /* STG,	     Stereographic projection   */
-            ProjectionType::Stg(_) => 360.0,
+            ProjectionType::Stg(_) => 360.0_f64.to_radians().to_angle(),
             /* SIN,	     Orthographic		        */
-            ProjectionType::Sin(_) => 180.0,
+            ProjectionType::Sin(_) => 180.0_f64.to_radians().to_angle(),
             /* ZEA,	     Equal-area 		        */
-            ProjectionType::Zea(_) => 360.0,
+            ProjectionType::Zea(_) => 360.0_f64.to_radians().to_angle(),
             /* FEYE,     Fish-eyes                  */
             //ProjectionType::Feye(_) => 190.0,
             /* AIR,                                 */
@@ -379,9 +381,9 @@ impl ProjectionType {
 
             // Pseudo-cylindrical projections
             /* AIT,      Aitoff                     */
-            ProjectionType::Ait(_) => 360.0,
+            ProjectionType::Ait(_) => 360.0_f64.to_radians().to_angle(),
             // MOL,      Mollweide                  */
-            ProjectionType::Mol(_) => 360.0,
+            ProjectionType::Mol(_) => 360.0_f64.to_radians().to_angle(),
             // PAR,                                 */
             //ProjectionType::Par(_) => 360.0,
             // SFL,                                 */
@@ -389,7 +391,7 @@ impl ProjectionType {
 
             // Cylindrical projections
             // MER,      Mercator                   */
-            ProjectionType::Mer(_) => 360.0,
+            ProjectionType::Mer(_) => 360.0_f64.to_radians().to_angle(),
             // CAR,                                 */
             //ProjectionType::Car(_) => 360.0,
             // CEA,                                 */
diff --git a/src/core/src/math/rotation.rs b/src/core/src/math/rotation.rs
index d66d9c96..c0ccd518 100644
--- a/src/core/src/math/rotation.rs
+++ b/src/core/src/math/rotation.rs
@@ -2,6 +2,7 @@ use crate::math;
 use cgmath::{BaseFloat, InnerSpace};
 use cgmath::{Euler, Quaternion};
 use cgmath::{Vector3, Vector4};
+use crate::math::angle::ToAngle;
 
 #[derive(Clone, Copy, Debug)]
 // Internal structure of a rotation, a quaternion
@@ -159,7 +160,7 @@ where
         let a = m.x.z.atan2(m.z.z);
         let b = (-m.z.y).atan2((S::one() - m.z.y * m.z.y).sqrt());
         let c = m.x.y.atan2(m.y.y);
-        (Angle(a), Angle(b), Angle(c))
+        (a.to_angle(), b.to_angle(), c.to_angle())
     }
 }
 
diff --git a/src/core/src/math/vector.rs b/src/core/src/math/vector.rs
index fb2c6cfc..df27ae13 100644
--- a/src/core/src/math/vector.rs
+++ b/src/core/src/math/vector.rs
@@ -1,15 +1,16 @@
 use crate::math::angle::Angle;
 use cgmath::{BaseFloat, InnerSpace, Vector2, Vector3};
+use crate::math::angle::ToAngle;
 
 #[inline]
 pub fn angle2<S: BaseFloat>(ab: &Vector2<S>, bc: &Vector2<S>) -> Angle<S> {
-    Angle((ab.dot(*bc)).acos())
+    ((ab.dot(*bc)).acos()).to_angle()
 }
 
 #[inline]
 pub fn angle3<S: BaseFloat>(x: &Vector3<S>, y: &cgmath::Vector3<S>) -> Angle<S> {
     let theta = x.cross(*y).magnitude().atan2(x.dot(*y));
-    Angle(theta)
+    theta.to_angle()
 }
 
 #[inline]
diff --git a/src/core/src/renderable/grid/label.rs b/src/core/src/renderable/grid/label.rs
index 75804e9d..ee135be7 100644
--- a/src/core/src/renderable/grid/label.rs
+++ b/src/core/src/renderable/grid/label.rs
@@ -6,12 +6,13 @@ use crate::ProjectionType;
 use cgmath::InnerSpace;
 use cgmath::Vector3;
 
-use crate::math::angle::SerializeFmt;
 use crate::math::lonlat::LonLat;
 use crate::math::projection::coo_space::XYScreen;
 use crate::math::TWICE_PI;
 
 use crate::math::angle::ToAngle;
+use crate::math::angle::AngleFormatter;
+use al_api::angle::Formatter;
 use cgmath::Vector2;
 use core::ops::Range;
 
@@ -22,7 +23,6 @@ pub enum LabelOptions {
     Centered,
     OnSide,
 }
-
 #[derive(Debug)]
 pub struct Label {
     // The position
@@ -39,7 +39,8 @@ impl Label {
         options: LabelOptions,
         camera: &CameraViewPort,
         projection: &ProjectionType,
-        _fmt: &SerializeFmt,
+        fmt: Formatter,
+        grid_decimal_prec: u8
     ) -> Option<Self> {
         let fov = camera.get_field_of_view();
         let d = if fov.contains_north_pole() {
@@ -76,8 +77,18 @@ impl Label {
             lon += TWICE_PI;
         }
 
-        //let content = fmt.to_string(lon.to_angle());
-        let content = al_api::angle_fmt::Format::toSexagesimal(lon.to_degrees() / 15.0, 8, false);
+        let mut angle = lon.to_angle();
+        let fmt = match fmt {
+            Formatter::Decimal => {
+                AngleFormatter::Decimal { prec: grid_decimal_prec }
+            },
+            Formatter::Sexagesimal => {
+                // Sexagesimal formatting for longitudes is HMS
+                AngleFormatter::Sexagesimal { prec: grid_decimal_prec, plus: false, hours: true }
+            }
+        };
+        angle.set_format(fmt);
+        let content = angle.to_string();
 
         let position = if !fov.is_allsky() {
             d1 + OFF_TANGENT * dt - OFF_BI_TANGENT * db
@@ -101,6 +112,8 @@ impl Label {
         options: LabelOptions,
         camera: &CameraViewPort,
         projection: &ProjectionType,
+        fmt: Formatter,
+        grid_decimal_prec: u8
     ) -> Option<Self> {
         let lonlat = match options {
             LabelOptions::Centered => {
@@ -130,8 +143,18 @@ impl Label {
         let dt = (d2 - d1).normalize();
         let db = Vector2::new(dt.y.abs(), dt.x.abs());
 
-        //let content = SerializeFmt::DMS.to_string(lonlat.lat());
-        let content = al_api::angle_fmt::Format::toSexagesimal(lonlat.lat().to_degrees(), 7, false);
+        let mut angle = lat.to_angle();
+        let fmt = match fmt {
+            Formatter::Decimal => {
+                AngleFormatter::Decimal { prec: grid_decimal_prec }
+            },
+            Formatter::Sexagesimal => {
+                // Sexagesimal formatting for latitudes is DMS with an optional '+' character
+                AngleFormatter::Sexagesimal { prec: grid_decimal_prec, plus: true, hours: false }
+            }
+        };
+        angle.set_format(fmt);
+        let content = angle.to_string();
 
         let fov = camera.get_field_of_view();
         let position = if !fov.is_allsky() && !fov.contains_pole() {
diff --git a/src/core/src/renderable/grid/meridian.rs b/src/core/src/renderable/grid/meridian.rs
index 12a2a7e0..fa4197c6 100644
--- a/src/core/src/renderable/grid/meridian.rs
+++ b/src/core/src/renderable/grid/meridian.rs
@@ -1,3 +1,5 @@
+use al_api::angle::Formatter;
+
 use super::label::{Label, LabelOptions};
 use crate::math::lonlat::LonLat;
 use crate::math::sph_geom::region::Intersection;
@@ -7,14 +9,14 @@ use core::ops::Range;
 use crate::math::MINUS_HALF_PI;
 use crate::ProjectionType;
 
-use super::angle::SerializeFmt;
 use crate::math::HALF_PI;
 
 pub fn get_intersecting_meridian(
     lon: f64,
     camera: &CameraViewPort,
     projection: &ProjectionType,
-    fmt: &SerializeFmt,
+    fmt: Formatter,
+    grid_decimal_prec: u8
 ) -> Option<Meridian> {
     let fov = camera.get_field_of_view();
     if fov.contains_both_poles() {
@@ -25,6 +27,7 @@ pub fn get_intersecting_meridian(
             camera,
             projection,
             fmt,
+            grid_decimal_prec
         );
         Some(meridian)
     } else {
@@ -39,6 +42,7 @@ pub fn get_intersecting_meridian(
                     camera,
                     projection,
                     fmt,
+                    grid_decimal_prec
                 );
                 Some(meridian)
             }
@@ -56,7 +60,7 @@ pub fn get_intersecting_meridian(
                             lat1..MINUS_HALF_PI
                         };
 
-                        Meridian::new(lon, &lat, LabelOptions::OnSide, camera, projection, fmt)
+                        Meridian::new(lon, &lat, LabelOptions::OnSide, camera, projection, fmt, grid_decimal_prec)
                     }
                     2 => {
                         // full intersection
@@ -73,56 +77,18 @@ pub fn get_intersecting_meridian(
                             camera,
                             projection,
                             fmt,
+                            grid_decimal_prec
                         )
                     }
-                    _ => {
-                        /*let mut vertices = vertices.into_vec();
-                        // One segment over two will be in the field of view
-                        vertices.push(Vector4::new(0.0, 1.0, 0.0, 1.0));
-                        vertices.push(Vector4::new(0.0, -1.0, 0.0, 1.0));
-
-                        vertices.sort_by(|i1, i2| {
-                            i1.y.total_cmp(&i2.y)
-                        });
-
-                        let v1 = &vertices[0];
-                        let v2 = &vertices[1];
-
-                        // meridian are part of great circles so the mean between v1 & v2 also lies on it
-                        let vm = (v1 + v2).truncate().normalize();
-
-                        let vertices = if !fov.contains_south_pole() {
-                            &vertices[1..]
-                        } else {
-                            &vertices
-                        };
-
-                        let line_vertices = vertices.iter().zip(vertices.iter().skip(1))
-                            .step_by(2)
-                            .map(|(i1, i2)| {
-                                line::great_circle_arc::project(
-                                    lon,
-                                    i1.lat().to_radians(),
-                                    lon,
-                                    i2.lat().to_radians(),
-                                    camera,
-                                    projection
-                                )
-                            })
-                            .flatten()
-                            .collect::<Vec<_>>();
-
-                        let label = Label::from_meridian(&v1.lonlat(), camera, projection, fmt);
-                        */
-                        Meridian::new(
-                            lon,
-                            &(-HALF_PI..HALF_PI),
-                            LabelOptions::OnSide,
-                            camera,
-                            projection,
-                            fmt,
-                        )
-                    }
+                    _ => Meridian::new(
+                        lon,
+                        &(-HALF_PI..HALF_PI),
+                        LabelOptions::OnSide,
+                        camera,
+                        projection,
+                        fmt,
+                        grid_decimal_prec
+                    )
                 };
 
                 Some(meridian)
@@ -139,7 +105,6 @@ pub struct Meridian {
     indices: Vec<Range<usize>>,
     label: Option<Label>,
 }
-
 impl Meridian {
     pub fn new(
         lon: f64,
@@ -147,9 +112,10 @@ impl Meridian {
         label_options: LabelOptions,
         camera: &CameraViewPort,
         projection: &ProjectionType,
-        fmt: &SerializeFmt,
+        fmt: Formatter,
+        grid_decimal_prec: u8
     ) -> Self {
-        let label = Label::from_meridian(lon, lat, label_options, camera, projection, fmt);
+        let label = Label::from_meridian(lon, lat, label_options, camera, projection, fmt, grid_decimal_prec);
 
         // Draw the full parallel
         let vertices = crate::renderable::line::great_circle_arc::project(
@@ -185,52 +151,6 @@ impl Meridian {
 
         indices.push(start_idx..vertices.len());
 
-        /*let mut prev_v = [vertices[0].x as f32, vertices[0].y as f32];
-        let vertices: Vec<_> = std::iter::once(prev_v)
-            .chain(
-                vertices.into_iter().skip(1)
-                    .filter_map(|v| {
-                        let cur_v = [v.x as f32, v.y as f32];
-                        if cur_v == prev_v {
-                            None
-                        } else {
-                            prev_v = cur_v;
-                            Some(cur_v)
-                        }
-                    })
-            )
-            .collect();
-
-        // Create subsets of vertices referring to different lines
-        let indices = if vertices.len() >= 3 {
-            let mut indices = vec![];
-
-            let mut v0 = 0;
-            let mut v1 = 1;
-            let mut v2 = 2;
-
-            let mut s = 0;
-
-            let n_segment = vertices.len() - 1;
-
-            for i in 0..n_segment {
-                if Triangle::new(&vertices[v0], &vertices[v1], &vertices[v2]).is_valid(camera) {
-                    indices.push(s..(i+1));
-                    s = i;
-                }
-
-                v0 = v1;
-                v1 = v2;
-                v2 = (v2 + 1) % vertices.len();
-            }
-
-            //indices.push(start_line_i..vertices.len());
-            //vec![0..vertices.len()]
-            vec![0..2]
-        } else {
-            vec![0..vertices.len()]
-        };*/
-
         Self {
             vertices,
             indices,
diff --git a/src/core/src/renderable/grid/mod.rs b/src/core/src/renderable/grid/mod.rs
index bc9bae4f..768c877c 100644
--- a/src/core/src/renderable/grid/mod.rs
+++ b/src/core/src/renderable/grid/mod.rs
@@ -8,7 +8,6 @@ use al_core::VecData;
 use parallel::Parallel;
 
 use crate::camera::CameraViewPort;
-use crate::math::angle;
 use crate::math::HALF_PI;
 use crate::ProjectionType;
 use al_api::color::ColorRGBA;
@@ -28,7 +27,7 @@ pub struct ProjetedGrid {
 
     // Render Text Manager
     text_renderer: TextRenderManager,
-    fmt: angle::SerializeFmt,
+    fmt: Formatter,
 
     //line_style: line::Style,
     meridians: Vec<Meridian>,
@@ -41,9 +40,8 @@ use crate::renderable::text::TextRenderManager;
 use crate::renderable::Renderer;
 use wasm_bindgen::JsValue;
 use web_sys::HtmlElement;
-
+use al_api::angle::Formatter;
 use self::meridian::Meridian;
-
 impl ProjetedGrid {
     pub fn new(gl: WebGlContext, aladin_div: &HtmlElement) -> Result<ProjetedGrid, JsValue> {
         let text_renderer = TextRenderManager::new(aladin_div)?;
@@ -58,7 +56,7 @@ impl ProjetedGrid {
         let enabled = false;
         let label_scale = 1.0;
         //let line_style = line::Style::None;
-        let fmt = angle::SerializeFmt::DMS;
+        let fmt = Formatter::Decimal;
         let thickness = 2.0;
         let meridians = Vec::new();
         let parallels = Vec::new();
@@ -150,7 +148,7 @@ impl ProjetedGrid {
         }
 
         if let Some(fmt) = fmt {
-            self.fmt = fmt.into();
+            self.fmt = fmt;
         }
 
         if let Some(label_size) = label_size {
@@ -210,6 +208,8 @@ impl ProjetedGrid {
                     (bbox.get_lon_size() as f64) * step_line_px / (camera.get_width() as f64);
                 let step_lon = select_fixed_step(step_lon_precised);
 
+                let decimal_lon_prec = step_lon.to_degrees().log10().abs().ceil() as u8;
+
                 // Add meridians
                 let start_lon = bbox.lon_min() - (bbox.lon_min() % step_lon);
                 let mut stop_lon = bbox.lon_max();
@@ -221,7 +221,7 @@ impl ProjetedGrid {
                 let mut lon = start_lon;
                 while lon < stop_lon {
                     if let Some(p) =
-                        meridian::get_intersecting_meridian(lon, camera, projection, &self.fmt)
+                        meridian::get_intersecting_meridian(lon, camera, projection, self.fmt, decimal_lon_prec)
                     {
                         meridians.push(p);
                     }
@@ -235,6 +235,8 @@ impl ProjetedGrid {
                     (bbox.get_lat_size() as f64) * step_line_px / (camera.get_height() as f64);
                 let step_lat = select_fixed_step(step_lat_precised);
 
+                let decimal_lat_prec = step_lat.to_degrees().log10().abs().ceil() as u8;
+
                 let mut start_lat = bbox.lat_min() - (bbox.lat_min() % step_lat);
                 if start_lat == -HALF_PI {
                     start_lat += step_lat;
@@ -244,7 +246,7 @@ impl ProjetedGrid {
 
                 let mut parallels = vec![];
                 while lat < stop_lat {
-                    if let Some(p) = parallel::get_intersecting_parallel(lat, camera, projection) {
+                    if let Some(p) = parallel::get_intersecting_parallel(lat, camera, projection, self.fmt, decimal_lat_prec) {
                         parallels.push(p);
                     }
                     lat += step_lat;
diff --git a/src/core/src/renderable/grid/parallel.rs b/src/core/src/renderable/grid/parallel.rs
index 11a8d7dd..c702fcb0 100644
--- a/src/core/src/renderable/grid/parallel.rs
+++ b/src/core/src/renderable/grid/parallel.rs
@@ -1,3 +1,5 @@
+use al_api::angle::Formatter;
+
 use super::label::Label;
 use crate::math::projection::ProjectionType;
 use crate::math::sph_geom::region::Intersection;
@@ -6,15 +8,17 @@ use crate::CameraViewPort;
 use crate::math::lonlat::LonLat;
 use crate::math::{PI, TWICE_PI};
 
-
 use crate::renderable::line;
 
 use core::ops::Range;
 
+
 pub fn get_intersecting_parallel(
     lat: f64,
     camera: &CameraViewPort,
     projection: &ProjectionType,
+    fmt: Formatter,
+    grid_decimal_prec: u8
 ) -> Option<Parallel> {
     let fov = camera.get_field_of_view();
     if fov.get_bounding_box().get_lon_size() > PI {
@@ -28,6 +32,8 @@ pub fn get_intersecting_parallel(
             camera,
             LabelOptions::Centered,
             projection,
+            fmt,
+            grid_decimal_prec
         ))
     } else {
         // Longitude fov < PI
@@ -43,6 +49,8 @@ pub fn get_intersecting_parallel(
                     camera,
                     LabelOptions::Centered,
                     projection,
+                    fmt,
+                    grid_decimal_prec
                 ))
             }
             Intersection::Intersect { vertices } => {
@@ -65,6 +73,8 @@ pub fn get_intersecting_parallel(
                     camera,
                     LabelOptions::OnSide,
                     projection,
+                    fmt,
+                    grid_decimal_prec
                 ))
             }
             Intersection::Empty => None,
@@ -89,8 +99,10 @@ impl Parallel {
         camera: &CameraViewPort,
         label_options: LabelOptions,
         projection: &ProjectionType,
+        fmt: Formatter,
+        grid_decimal_prec: u8
     ) -> Self {
-        let label = Label::from_parallel(lat, lon, label_options, camera, projection);
+        let label = Label::from_parallel(lat, lon, label_options, camera, projection, fmt, grid_decimal_prec);
 
         // Draw the full parallel
         let vertices = if lon.end - lon.start > PI {
@@ -109,24 +121,6 @@ impl Parallel {
             line::parallel_arc::project(lat, lon.start, lon.end, camera, projection)
         };
 
-        /*let mut prev_v = [vertices[0].x as f32, vertices[0].y as f32];
-        let vertices: Vec<_> = std::iter::once(prev_v)
-            .chain(
-                vertices.into_iter().skip(1)
-                    .filter_map(|v| {
-                        let cur_v = [v.x as f32, v.y as f32];
-                        if cur_v == prev_v {
-                            None
-                        } else {
-                            prev_v = cur_v;
-                            Some(cur_v)
-                        }
-                    })
-            )
-            .collect();
-
-        let indices = vec![0..vertices.len()];
-        */
         let mut start_idx = 0;
 
         let mut indices = if vertices.len() >= 3 {
diff --git a/src/core/src/renderable/hips/d2/mod.rs b/src/core/src/renderable/hips/d2/mod.rs
index 8e94847f..6ea90ef8 100644
--- a/src/core/src/renderable/hips/d2/mod.rs
+++ b/src/core/src/renderable/hips/d2/mod.rs
@@ -19,7 +19,6 @@ use al_core::VecData;
 use al_core::VertexArrayObject;
 use al_core::WebGlContext;
 
-use crate::math::angle::Angle;
 use crate::ProjectionType;
 
 use crate::camera::CameraViewPort;
@@ -31,6 +30,8 @@ use crate::downloader::request::allsky::Allsky;
 use crate::healpix::{cell::HEALPixCell, coverage::HEALPixCoverage};
 use crate::renderable::utils::index_patch::DefaultPatchIndexIter;
 use crate::time::Time;
+use crate::math::angle::ToAngle;
+
 
 use super::config::HiPSConfig;
 use std::collections::HashSet;
@@ -565,7 +566,7 @@ impl HiPS2D {
                         self.uv_end.extend(uv_end);
                         self.time_tile_received.push(start_time);
 
-                        let xyz = crate::math::lonlat::radec_to_xyz(Angle(lon), Angle(lat));
+                        let xyz = crate::math::lonlat::radec_to_xyz(lon.to_angle(), lat.to_angle());
                         pos.push([xyz.x as f32, xyz.y as f32, xyz.z as f32]);
                         //pos.push([lon as f32, lat as f32]);
                     }
diff --git a/src/core/src/renderable/hips/subdivide.rs b/src/core/src/renderable/hips/subdivide.rs
index b3b63544..095edc51 100644
--- a/src/core/src/renderable/hips/subdivide.rs
+++ b/src/core/src/renderable/hips/subdivide.rs
@@ -1,19 +1,17 @@
 use crate::camera::CameraViewPort;
-use crate::math::angle::Angle;
 use crate::math::projection::ProjectionType;
 use crate::math::vector::dist2;
 use crate::HEALPixCell;
-
+use crate::math::angle::ToAngle;
 const M: f64 = 280.0 * 280.0;
 const N: f64 = 150.0 * 150.0;
 const RAP: f64 = 0.7;
-
 fn is_too_large(cell: &HEALPixCell, camera: &CameraViewPort, projection: &ProjectionType) -> bool {
     let vertices = cell
         .vertices()
         .iter()
         .filter_map(|(lon, lat)| {
-            let vertex = crate::math::lonlat::radec_to_xyzw(Angle(*lon), Angle(*lat));
+            let vertex = crate::math::lonlat::radec_to_xyzw(lon.to_angle(), lat.to_angle());
             projection.icrs_celestial_to_screen_space(&vertex, camera)
         })
         .collect::<Vec<_>>();
diff --git a/src/js/Aladin.js b/src/js/Aladin.js
index e42123e0..fd0011b2 100644
--- a/src/js/Aladin.js
+++ b/src/js/Aladin.js
@@ -1416,6 +1416,12 @@ export let Aladin = (function () {
         this.view.showCatalog(show);
     };
 
+    /**
+     * Show/Hide the reticle centered on the view
+     *
+     * @memberof Aladin
+     * @param {boolean} show - True to enable, false to hide
+     */
     Aladin.prototype.showReticle = function (show) {
         this.reticle.update({ show });
     };
@@ -1433,6 +1439,12 @@ export let Aladin = (function () {
         });
     };
 
+     /**
+     * Add a overlay of shapes/footprints to the view
+     *
+     * @memberof Aladin
+     * @param {GraphicOverlay} overlay - The shapes/footprints overlay to add
+     */
     Aladin.prototype.addOverlay = function (overlay) {
         this.view.addOverlay(overlay);
 
@@ -1441,10 +1453,15 @@ export let Aladin = (function () {
         });
     };
 
+
+    /**
+     * Add a Multi-Order Coverage map (MOC) to the view
+     *
+     * @memberof Aladin
+     * @param {MOC} moc - The MOC object to add
+     */
     Aladin.prototype.addMOC = function (moc) {
         this.view.addMOC(moc);
-
-        // see MOC.setView for sending it to outside the UI
     };
 
     Aladin.prototype.removeUIByName = function(name) {
@@ -3078,12 +3095,5 @@ aladin.displayFITS(
         });
     };
 
-    /*
-    Aladin.prototype.setReduceDeformations = function (reduce) {
-        this.reduceDeformations = reduce;
-        this.view.requestRedraw();
-    }
-    */
-
     return Aladin;
 })();
diff --git a/src/js/AladinUtils.js b/src/js/AladinUtils.js
index 43db0a04..be19dc0d 100644
--- a/src/js/AladinUtils.js
+++ b/src/js/AladinUtils.js
@@ -208,6 +208,7 @@ export let AladinUtils = {
         * // returns "36 arcsec"
         * Numbers.degreesToString(0.01);
         */
+        // FIXME: Same as in the libs/astro/angle.js
         degreesToString: function(numberDegrees) {
             let setPrecision = 3
             let degrees = numberDegrees | 0;
diff --git a/src/js/View.js b/src/js/View.js
index 55b1a28f..f674f456 100644
--- a/src/js/View.js
+++ b/src/js/View.js
@@ -1966,11 +1966,11 @@ export let View = (function () {
         }
 
         // Set the grid label format
-        if (this.cooFrame.label == "ICRSd") {
-            this.setGridOptions({fmt: "HMS"});
+        if (this.cooFrame.label == "ICRS") {
+            this.setGridOptions({fmt: "sexagesimal"});
         }
         else {
-            this.setGridOptions({fmt: "DMS"});
+            this.setGridOptions({fmt: "decimal"});
         }
 
         // Get the new view center position (given in icrs)