Material:9-speed cassette Made of metal, corrosion-resistant and durable. The internal thread has high accuracy, smooth rotation and easy maintenance Speed Changer:9 Speed Cassette The vacuum coating technology makes the surface of this flywheel fine and smooth. It is equipped with precise gear design, which is light, smooth and stable while driving, and accelerates quickly, can effectively prevent the chain from falling off. Easy to Install:9 Speed Freewheel Easy to install, no need to adjust the shifting and directly replace the old damaged flywheel, it is a great accessory for mountain bikes and variable speed bikes. Application:9 Speed Freewheel is one of the strongest and most durable flywheels on multi-speed bicycles. Suitable for mountain bikes and folding bikes, hybrid bikes, city bikes, fat bikes, beach cruising bikes and so on. Note: SRAM XD system is not supported and can only be used for Shimano HG system freehubs 9 speed cassette gear 11-36T: 11-13-15-18-21-24-28-32-36T 11-40T: 11-13-15-18-21-24-28-34-40T 11-42T: 11-13- 16-20-24-28-32-36-42T 11-46T: 11-13-16-20-24-28-34-40-46T 11-50T: 11-13-16-20-24-30- 36-42-50T MATERIALS:The mountain bike 9 Speed cassette made of high pressure steel is durable, nickel and chrome plating. COMPATIBILITY: Compatible with most mountain bike cassette flywheels, such as SHIMANO HG With hollow design, weight reduction, super wear-resistant steel. Which is lighter, smooth and stable while driving and accelerates quickly, and it can effectively prevent the chain from falling off. performance:Precise, consistent shifting performance Hyperglide widely used:Suitable for MTB and Hybrid bikes Easy to install Easy to install, no need to adjust the gearbox, directly replace the old or damaged flywheel It is an excellent accessory for mountain bikes and variable speed bikes Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.