Shimano Deore XT RD-M8050 Di2 Rear Derailleur - FEATURES: Accurate and stable shifting in any condition Customized shift speed within Multi-shift Smart and efficient gear selection with Shimano Synchro Shift SPECS: Color: Black Largest Cog: 40 Rear Derailleur Mount Type: 10x1 Standard , Shimano Rear Direct Mount Chain Wrap Capacity (teeth): 33 Cage Length: Medium Rear Der/Shifter Compatibility: Shimano Mountain Di2 Drivetrain Speeds: 11