diff --git a/geodataset/custom_geodataset.py b/geodataset/custom_geodataset.py
index e8ca51f..c391d65 100644
--- a/geodataset/custom_geodataset.py
+++ b/geodataset/custom_geodataset.py
@@ -76,7 +76,7 @@ def get_lonlat_arrays(self, ij_range=(None,None,None,None), **kwargs):
         i0, i1, j0, j1 = ij_range
         x_grd, y_grd = np.meshgrid(self['x'][j0:j1], self['y'][i0:i1])
         return self.projection(x_grd, y_grd, inverse=True)
-    
+
 
 class NERSCDeformation(NERSCProductBase):
     pattern = re.compile(r'arctic_2km_deformation_\d{8}T\d{6}.nc')
@@ -87,7 +87,7 @@ class NERSCIceType(NERSCProductBase):
 
 
 class NERSCSeaIceAge(NERSCProductBase):
-    pattern = re.compile(r'arctic25km_sea_ice_age_v2p0_\d{8}.nc')
+    pattern = re.compile(r'arctic25km_sea_ice_age_v2p1_\d{8}.nc')
 
 
 class OsisafDriftersNextsim(CustomDatasetRead):
diff --git a/geodataset/tests/test_custom_geodataset.py b/geodataset/tests/test_custom_geodataset.py
index b425324..1746d53 100644
--- a/geodataset/tests/test_custom_geodataset.py
+++ b/geodataset/tests/test_custom_geodataset.py
@@ -55,24 +55,53 @@ def test_get_lonlat_arrays(self):
             __init__=MagicMock(return_value=None),
             filepath=DEFAULT,
             )
-    def test_datetimes_1(self, **kwargs):
-        """ test for older filename """
-        dto = dt.datetime(2017,5,1)
+    def test_datetimes(self, **kwargs):
+        dto = dt.datetime(2023,5,1,12)
         kwargs['filepath'].return_value = dto.strftime('a/b/mpd_%Y%m%d.nc')
         obj = UniBremenAlbedoMPF()
         self.assertEqual(obj.datetimes, [dto])
 
 
-    @patch.multiple(UniBremenAlbedoMPF,
+class NERSCProductBaseTest(BaseForTests):
+
+    @property
+    def x(self):
+        return np.linspace(0.,1.,6)
+
+    @property
+    def y(self):
+        return np.linspace(1.,2.,8)
+
+    @patch.multiple(NERSCProductBase,
             __init__=MagicMock(return_value=None),
-            filepath=DEFAULT,
+            __getitem__=DEFAULT,
+            projection=DEFAULT,
             )
-    def test_datetimes_2(self, **kwargs):
-        """ test for newer filename """
-        dto = dt.datetime(2021,5,1)
-        kwargs['filepath'].return_value = dto.strftime('a/b/mpd_%Y%m%d_NR.nc')
-        obj = UniBremenAlbedoMPF()
-        self.assertEqual(obj.datetimes, [dto])
+    def test_get_lonlat_arrays(self, __getitem__, projection):
+        """ test for older filename """
+        def mock_getitem(key):
+            if key == "x":
+                return self.x
+            return self.y
+
+        obj = NERSCProductBase()
+        __getitem__.side_effect = mock_getitem
+        projection.return_value = ('lon', 'lat')
+
+        i0 = 2
+        i1 = 5
+        j0 = 1
+        j1 = 6
+        x0, y0 = np.meshgrid(self.x[j0:j1], self.y[i0:i1])
+
+        lon, lat = obj.get_lonlat_arrays(ij_range=(i0, i1, j0, j1))
+        self.assertEqual(lon, 'lon')
+        self.assertEqual(lat, 'lat')
+        self.assertEqual(__getitem__.mock_calls, [call('x'), call('y')])
+        x, y = projection.mock_calls[0][1]
+        self.assertTrue(np.allclose(x, x0))
+        self.assertTrue(np.allclose(y, y0))
+        self.assertEqual(projection.mock_calls[0][2], dict(inverse=True))
 
 
 if __name__ == "__main__":
diff --git a/geodataset/tests/test_tools.py b/geodataset/tests/test_tools.py
index 789ae19..fc5ca7c 100644
--- a/geodataset/tests/test_tools.py
+++ b/geodataset/tests/test_tools.py
@@ -29,7 +29,6 @@ def test_open_netcdf(self):
 
     def test_get_lonlat_arrays(self):
         for nc_file in self.nc_files:
-            print(nc_file)
             with self.subTest(nc_file=nc_file):
                 with open_netcdf(nc_file) as ds:
                     if not ds.is_lonlat_2d: