Features 1、Made of high strength steel, plated with nickel and chromiums, it is wear resistant, durable, high temperature resistant, corrosion resistant, rust proof, non deformation, impact resistant, high accurancy tooth profiles, toothless design, and strong compatibility. 2、Provides fast and accurate indexing conversion function through special tooth profiles and slope. Lost tooth design, special shaped irregular cut angle tooth profiles, better compatibility with gear shifting chain, and glossy shifting and shifting. 3、The hollow design can easily reduce the weight, professional manufacturing,reduce the burden of riding, achieve a good balance between strength and weight, easy to install and use, and is an ideal choice for reducing the weight of the bicycle. 4、Independent small tooth rings, the small teeth of the bicycle cassette flywheel are often used during use, and the independent small tooth design is convenient for future replacement and maintenance.Can be used for a long time. 5、Easy to install, professional manufacturing, direct replacement of old or damaged flywheels, excellent accessories, easy to install, without any adjustment to the shifting system; unique mountain bike chain design, can well control the shifting function. Item Type: 9 Speed Bicycle Flywheel Material: High Strength Steel Speed: 9 Speed Number of Gear Teeth: 11-13-15-17-21-24-28-32-36T Package List 1 x Bicycle Flywheel 2 x Rings Gear 1 x Lock Rings