Feature: 1. Hollow out design, reducing weight, can also effectively increase speed at the same time. 2. High-precision tooth shape, strong compatibility, provide a better riding experience. 3. Powerful corrosion resistance, rust resistance, high durability, strong impact resistance. 4. Easy to install without any adjustment, effectively save your time. 5. Chain groove and mud hole design, make mud drainage hole makes it easier to clean and not easy to drop chain. Specification: Item Type: Bicycle FlywheelMaterial: Chromium-Molybdenum SteelWeight: Approx. 600g/ 21.2oz Quantity: 1PCSSpecification: 11 Speed, 11-46TSmall Teeth: 11TNumber of Teeth: 11-13-15-18-21-24-28-32-36-40-46TLarge Tooth Black Piece: 46T . Package List: 1 x Bicycle Flywheel