S10 Description:

This part is used on Shimano Shadow rear derailleurs starting 2013

Will fit a cassette size of 40T or bigger

Bolt included

Improves shifting performance on 1-10 systems

Increases chain wrap, eliminates the need to drastically thread in the b-tension screw

Replaces the Direct Mount link on 2013 or later Shimano 10-speed Shadow rear derailleurs to reduce premature shifting degradation

Works with any 11-40t or 11-42t 10-speed cassette