diff --git a/cs_storage/__init__.py b/cs_storage/__init__.py
index 44ee0c1..9bd73a8 100644
--- a/cs_storage/__init__.py
+++ b/cs_storage/__init__.py
@@ -18,6 +18,9 @@
 
 
 class Serializer:
+    """
+    Base class for serializng input data to bytes and back.
+    """
     def __init__(self, ext):
         self.ext = ext