The Shimano Deore XT M8100 / M8200 12-speed Upgrade Kit includes everything needed to enhance your drivetrain. The RD-M8100 Rear Derailleur ensures smooth, efficient shifting and supports cassettes up to 51 teeth. The M8200 cassette features Rider Tuned gear steps for optimal cadence control across diverse mountain bike terrain. Featuring RapidFire Plus technology, the shift lever allows for rapid shifting, enabling you to downshift up to four gears with a single stroke. Additionally, the M8100 chain delivers dependable shifting performance. Deore XT Upgrade Kit Includes Shimano CS-M8200 Cassette Cassette Cogs: 10-51t: 10-12-14-16-18-21-24-28-33-39-45-51t Material: Steel, and alloy cogs Compatible Freehub: Shimano Microspline Shimano RD-M8100 Rear Derailleur Cage Length: SGS/Long Max Low Sprocket: 51t Pulley size: 13t Shimano SL-M8100 Shift Lever Mount: 22.2mm clamp or I-Spec EV Max multiple shifts: 4 Shifter type: Rapidfire Plus Included Derailleur Cable: Optislick Shimano CN-M8100 Chain Number of links: 138 Quick link included (SM-CN910-12)