I have one of these on a pinch pin that adds additional security to stop the pin being able to be pulled through the rear hub of my GS
It fits perfectly in the recess, however I did add some felt around the edge to save any scratches

This isn't so much a washer as an Olympic discus! It's a heavy duty chunk of metal that helps to make the Anti-Pinch Pin impossible to pass through the frame.

Plain and simple way to increase the size of the head for the anti-pinch washer.
Can't say much other than IT WORKS ;)

Anti-Pinch Pin Washer what a great peace of kit, This works great along with the mini pinch pin and fits through my SP2 swing arm perfect.
Excellent quality and worth every penny.