diff --git a/sonic_fan/fan_base.py b/sonic_fan/fan_base.py
index 1ea8836b7..6643bfa0c 100644
--- a/sonic_fan/fan_base.py
+++ b/sonic_fan/fan_base.py
@@ -66,8 +66,8 @@ def get_speed(self, index):
 
     def get_speed_rear(self, index):
         """
-        Retrieves the speed of a rear FAN in the tray in revolutions per minute defined
-                by 1-based index <index>
+        Retrieves the speed of a rear FAN in the tray (applicable only for 2-fan tray) 
+                in revolutions per minute defined by 1-based index <index>
 
         :param index: An integer, 1-based index of the FAN of which to query speed
         :return: integer, denoting rear FAN speed