XTR M9250-SGS Di2 Wireless 12-Speed Rear Derailleur - 10-51T

The all-new XTR M9250 long-cage derailleur paired with a standard 10-51T M9200 cassette gives riders and racers the speed, range, and robustness to tackle every trail on the mountain. With built-in Automatic Impact Recovery, an impact-deflecting shape, and simple covered-pulley solutions, this derailleur stands up to harsh trail impacts and still retains its lightning-quick shifting speed and top-level performance.