Sram: ONE HARD-WORKING HANGER. The Universal Derailleur Hanger consolidates thousands of hanger options across the industry. It protects your derailleur against chain jams by pivoting back and out of the way, and slips slightly when encountering impacts. It improves shifting performance, guarantees better alignment, and works with all drivetrains. Plus, if you ever need replacement, it will be available everywhere. The UDH. One hard-working hanger.FEATURESThe Universal Derailleur Hanger – or UDH – consolidates thousands of mountain bike derailleur standards.It offers unparalleled derailleur protection. And perfect alignment. Guaranteed.The 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.The UDH works with all commercially available MTB and E-MTB drivetrains from Shimano to Box to Sunrace.