diff --git a/docs/usermanual.md b/docs/usermanual.md
index 36f21779..0e344e28 100644
--- a/docs/usermanual.md
+++ b/docs/usermanual.md
@@ -294,8 +294,11 @@ Robot1@turn|left
 
 ##### Time processing
 
-HTTP bindig is returning in a HTTP header named `X-Processing-Time` processing time expended by current HTTP measure
-request.
+HTTP bindig is returning in a HTTP header named `X-Processing-Time` processing time (in milliseconds) expended by current HTTP measure
+request. For example:
+```
+X-Processing-Time: 38 ms 
+```
 
 #### MQTT binding