The Shimano Deore M5100 11-speed Upgrade Kit includes everything needed to enhance your drivetrain. The RD-M5100 Rear Derailleur ensures smooth, efficient shifting and supports the 51 tooth cassette. The cassette is designed with Rider Tuned gear steps for optimal cadence control on diverse mountain bike terrain. Featuring RapidFire Plus technology, the shift lever allows for rapid shifting, enabling you to downshift up to three gears with a single stroke. Additionally, the HG601 chain delivers dependable shifting performance with its asymmetric plate design. Deore M5100 Upgrade Kit Includes Shimano CS-M5100 Cassette Cassette Cogs: 11-51t: 11-13-15-18-21-24-28-33-39-45-51t Finish: Plated Compatible Freehub: Shimano HG Shimano RD-M5100 Rear Derailleur Cage Length: SGS/Long Max Low Sprocket: 51t Pulley size: 13t Shimano SL-M5100 Shift Lever Mount: 22.2mm clamp or I-Spec EV Max multiple shifts: 3 Shifter type: Rapidfire Plus Included Derailleur Cable: Optislick Shimano CN-HG601-11 Chain Number of links: 126 Quick link included (SM-CN900-11) Shimano Deore Ecosystem and compatability