The all-new SHIMANO DEORE XT M8100 series of derailleurs brings a new level of drivetrain silence thank to decreased tension in the low gear position and an added bumper on the pulley cage. Larger 13T pulleys increase efficiency and chain management while compatibility with SHIMANO's new 12-speed cassettes boosts range. FEATURES: Offers fast and shockless shifting thanks to HYPERGLIDE+ technology The low-profile design includes a bumper added to the derailleur pulley cage Shimano Shadow RD+ technology reduces chain slap and creates a quieter drivetrain Includes large 13t pulley Drivetrain is silent in all gear positions with decreased rear derailleur and chain tension in low gear Long cage is designed to be used with 1x12 drivetrain systems SPECS: Largest Cog: 51 Rear Derailleur Mount Type: 10x1 Standard Chain Wrap Capacity (teeth): 41 Cage Length: Long Rear Der/Shifter Compatibility: Shimano Mountain Drivetrain Speeds: 12 Weight: 284