diff --git a/lcviz/helper.py b/lcviz/helper.py
index 143d076..a3b6d57 100644
--- a/lcviz/helper.py
+++ b/lcviz/helper.py
@@ -17,6 +17,7 @@
 @unit_converter('custom-lcviz')
 class UnitConverter:
     def equivalent_units(self, data, cid, units):
+        print("***", cid, units)
         return set(list(map(str, u.Unit(units).find_equivalent_units(
                     include_prefix_units=True, equivalencies=u.spectral()))))