Gear ratio: It can meet the replacement of most mountain bike cassette flywheel 12-speed 11-52T, 11-13-15-18-21-24-28-32-36-46-52T Material: 12-speed cassette Made of metal, corrosion-resistant and durable. The internal thread has high accuracy, smooth rotation and easy maintenance Material:12-speed cassette Made of metal, corrosion-resistant and durable. The internal thread has high accuracy, smooth rotation and easy maintenance Speed Changer:12 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:12 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:12 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 12 speed cassette gear 11-46T: 11-13-15-17-19-21-24-28-32-36-40-46T 11-50T: 11-13-15-17-19-21-24-28-32-36 -42-50T 11-52T:11-13-15-18-21-24-28-32-36-40-46-52T MATERIALS:The mountain bike 12 Speed cassette made of high pressure steel is durable, nickel and chrome plating. COMPATIBILITY:Compatible with most mountain bike cassette flywheels, such as SHIMANO HGWith 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 Hyperglidewidely used:Suitable for MTB and Hybrid bikesEasy to installEasy to install, no need to adjust the gearbox, directly replace the old or damaged flywheelIt 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.