The Shimano Deore XT M8250 long-cage derailleur paired with a standard 10-51t M8200 cassette (cassette sold separate) gives all types of riders the range and robustness to tackle every trail on the mountain. With built-in Automatic Impact Recovery, a new, impact-deflecting wedge shape, and simple covered-pulley solutions, this derailleur stands up to harsh trail impacts and still retains its lightning-quick shifting speed and high level of performance.