Specifications Hign-concerned Chemical:None Model Number:CS-HG51-8 Sensitivity:36 Sounds Flywheel Adjustable Gear Number:8-speed Material:STEEL Gear Teeth:11-32T Freewheel Speed:8 Origin:ID(Origin) Components:Freewheel CS-HG51-8 Cassette The CS-HG51-8 is an 8-speed cassette at Alivio level. It features Hyperglide (HG) technology for precise, smooth shifting and is designed for trekking and MTB use. Compared to previous 8-fold and 7-fold cassettes, it is characterized by a lower weight. Use:All Mountain, Touring and Trekking Speed:8-Speed Chainring: 11-28T (11-13-15-17-19-21-24-28T) 11-30T (11-13-15-17-20-23-26-30T) 11-32T (11-13-15-18-21-24-28-32T) Weight:Approx 286g(11-30T), 306g(11-32T) Freewheel compatibility: MTB Features: HG cassette with chromed steel pinions Fast assembly Lower weight Larger pinion window for lower weight Tech: HG cassette Hyperglide cassettes (HG cassettes) have strategically positioned climbing aids and special tooth profiles so that the chain can be guided directly to the next sprocket. This prevents the chain from only touching the tooth tips before putting it on properly. This optimizes chain guidance and enables fast, highly efficient shifting.