diff --git a/Ploopy-Nano-Trackball-Kit-Assembly.md b/Ploopy-Nano-Trackball-Kit-Assembly.md
index d4e275a..df616fd 100644
--- a/Ploopy-Nano-Trackball-Kit-Assembly.md
+++ b/Ploopy-Nano-Trackball-Kit-Assembly.md
@@ -128,7 +128,7 @@ Prepare the following components:
 
 ![friction pads](https://lh3.googleusercontent.com/pw/ACtC-3eziZk9O8j8vag93XDSrY5OZXGc2pFEVUK70wDWIL3WEMPl_KW9-a0p6KlV2F9eUmJGPECi_iUXXrR-teHK3SjVzdf13kEGEax_xVHqq5IN79GolLeC4DE9IjrTO0QJSEuyyKo-s1AechC5ZA8laqTT=w1068-h801-no?authuser=0)
 
-## Step 17: Remove a bit of shine from the ball
+## Step 17 (OPTIONAL): Remove a bit of shine from the ball
 
 ![rubbing ball](https://lh3.googleusercontent.com/pw/ACtC-3frmIPsen7qfeDoD6m-EnXQGOjiUJqeyGgMcVIoJXzCN2ZgIh-Xd4qyybv_wyCh2UF9OaaCMZx36sbO7LQCGQnI2aXD4F04sSNAWblfHTyBTBzSUqibdYfhPFRY-E3iWgL-WPMTttN6-B9m3G3ccsW4=w1069-h801-no?authuser=0)