Specifications Hign-concerned Chemical:None Model Number:CS-HG50-9 Sensitivity:108 Sounds Flywheel Adjustable Gear Number:9-speed Material:STEEL Gear Teeth:11-25T Freewheel Speed:9 Origin:Jp(origin) Components:Freewheel Deore-Alivio HG50 9-Speed Cassette Computer designed Hyperglide (HG) sprockets incorporate specifically positioned shift ramps and tooth profiles for improved chain control during shifting. Fast and responsive indexed shifting is the result. Features: High quality 9-speed cassette Hyperglide sprockets have a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load Close ratio gearing allows a more efficient use of energy through finer cadence control Sprockets are cut away and drilled to reduce weight without reducing rigidity Nickel-plated finish offers hard wearing resistance to corrosion Corrosion-resistant steel cassette lockring For Super Narrow 9-speed HG chains Specifications: Alloy Sprocket Carrier: no Number of Sprockets: 9-speed HG Sprocket Material: steel Sprocket Finish: Ni-plated Chain Compatibility: Super Narrow HG Cassette Option 11-25T: 11-12-13-15-17-19-21-23-25T Cassette Option 12-25T: 12-13-14-15-17-19-21-23-25T Weight: 224g (11-25T)