The SRAM Universal Derailleur Hanger (UDH) consolidates thousands of hanger options across the industry, while protecting your derailleur against chain jams by pivoting back and out of the way, and slipping slightly when encountering impacts. It improves shifting performance, guarantees better alignment, and works with all drivetrains. The Universal Derailleur Hanger consolidates thousands of mountain bike derailleur standards UDH is designed to rotate rearward in the event of impact, and features the ability to "re-rail" the chain back onto the small cog It works with all commercially available MTB and E-MTB drivetrains from Shimano to Box to Sunrace