diff --git a/pytorch_lightning/plugins/precision/precision_plugin.py b/pytorch_lightning/plugins/precision/precision_plugin.py
index 22c1a7539fff4e..031b5887376147 100644
--- a/pytorch_lightning/plugins/precision/precision_plugin.py
+++ b/pytorch_lightning/plugins/precision/precision_plugin.py
@@ -22,6 +22,9 @@
 
 
 class PrecisionPlugin(Plugin):
+    """ Plugin handling the precision-specific parts of the training.
+    The static classattributes EPSILON and precision must be overwritten in child-classes and their default values reflect fp32 training
+    """
     EPSILON = 1e-6
     precision = 32