Specifications: The 10-speed variable-speed road bicycle cassette flywheel is compatible with the transmission systems of major bike brands. Made of high-strength steel, quenched and tempered, it has high strength, durability and strong abrasion resistance. Strong oxidation resistance, not easy to rust, and long service life. Due to the unique design of the car sprocket, the shifting function can be well controlled. The surface is made of vacuum colorful plating process, no discoloration on the electroplated surface, the surface is more beautiful, giving a luxurious feel. The hollow design reduces weight. Item Name: Flywheel Material: Chrome Molybdenum Steel Speed: 10 Speed Teeth: 11-28T(11-12-13-15-17-19-21-23-25-28T) Features: Durable, Ultra-light, Easy to Install, Bike Accessories Size: 12cm x 12cm x 5cm/4.72" x 4.72" x 1.97" (Approx.) Notes: 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. Package Includes: 1 x Flywheel