* The Universal Derailleur Hanger (UDH™) consolidates thousands of mountain bike derailleur standards.* Unparalleled derailleur protection. And perfect alignment. Guaranteed.* Designed to rotate rearward in the event of impact and features the ability to “re-rail” the chain back onto the small cog.* Works with all commercially available MTB and E-MTB drivetrains from Shimano to Box to Sunrace.