Shimano SLX HG81 10-Speed CassetteThe Shimano SLX HG81 10-speed mountain bike cassette is lightweight, rigid and designed to deliver the precise, responsive shifting performance and worry-free dependability that off-road riders demand. Four largest sprockets are mounted on a lightweight alloy carrier to reduce weight and increase rigidity Sprockets are milled and drilled to reduce weight while retaining rigidity Special computer-designed tooth configuration with contoured shift gates for precise, smooth shifting, even under load Close-ratio gearing lets you better control cadence for improved energy transfer efficiency Compatible with super-narrow 10-speed Hyper Glide chains only | Shimano SLX CS-Hg81 10 Speed Cassette 11-34T