Shimano M5100 Deore 11 Speed CassetteEngineered for reliable performance on every MTB ride, this 11 speed cassette gives you smooth shifting operation from its lightweight and minimal design sprocket carrier. It features Hyperglide sprockets, which use a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load. Its sprockets are also cut away and drilled to reduce weight without reducing rigidity. One final highlight is its close ratio gearing allows a more efficient use of energy through finer cadence control.Features: Use: MTB Speed: 11 speed Sprockets: Hyperglide sprockets Chain Compatibility: For 11-speed HG-EV MTB chains Ratio: Mutliple options availablePart Numbers: 11-42T: CSM5100142; 11-51T: CSM5100151Technologies: Hyperglide Sprockets: Hyperglide sprockets have a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load. Sprockets are cut away and drilled to reduce weight without reducing rigidity. Close Ratio Gearing: Close ratio gearing allows a more efficient use of energy through finer cadence control.A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.