Feature:1. High temperature resistance, resistance, rust resistance, no deformation, high durability, strong impact resistance.2. Adopt hollow out design, as well as reducing weight, can effectively increase speed.3. Made of high quality chromium-molybdenum steel , more firm and durable, provide longer service life.4. Easy to install, simple structure, easy to screw into the hub, provide fast speed with less effort, specially designed for gear shifting and longlasting performance.5. Light in weight, will not bring burden to your bicycle, ensure a perfect performance.Specification:Item Type: Bicycle FlywheelMaterial: Chromium-Molybdenum SteelWeight: Approx. 541g/ 19.1oz Color: Black+ GoldenQuantity: 1PCSSpecification: 9 Speed, 11-46TSmall Teeth: 11TNumber of Teeth: 11-13-16-20-24-28-34-40-46TLarge Tooth Black Part: 46TPackage List:1 x Bicycle Flywheel