diff --git a/DDSim/Helper/Gun.py b/DDSim/Helper/Gun.py
index a4cce5d7d6c5cd9634c742d2df3aeb8efc39162c..2ccac701e1a557493072a1d908813cf0bbdf3c13 100644
--- a/DDSim/Helper/Gun.py
+++ b/DDSim/Helper/Gun.py
@@ -20,7 +20,11 @@ class Gun( ConfigHelper ):
 
   @property
   def isotrop( self ):
-    """ isotropic distribution for the particle gun """
+    """ isotropic distribution for the particle gun
+
+    use the options phiMin, phiMax, thetaMin, and thetaMax to limit the range of randomly distributed directions
+    if one of these options is not None the random distribution will be set to True and cannot be turned off!
+    """
     return self._isotrop
   @isotrop.setter
   def isotrop( self, val ):