Deore XT RD-M8100 Rear Derailleur 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 2x12 drivetrain systems SPECS : Color: Black Largest Cog: 45 Rear Derailleur Mount Type: 10x1 Standard Chain Wrap Capacity (teeth): 45 Cage Length: Long Rear Der/Shifter Compatibility: Shimano Mountain Drivetrain Speeds: 12 Weight: 284