Feature:1. 3 Layers Nickel Plating: This bike flywheel is finely quenched, tempered and hardened, with 3 layer nickel plating, wear resistant and rust proof.2. Accuracy Thread: The thread of the flywheel is clear and firm, the flywheel and the hub are closely connected, and the operation is smoother.3. Strong Compatibility: High accuracy positioning of the tooth shape, fluent shifting, punching to reduce weight, and strong compatibility!4. Low Noise Operation: The flywheel rotates smoothly and without noise, ensuring tight connection with the bike hub and stable operation.5. Product Style: It is a silver 7 speed threaded flywheel with 13, 15, 17, 19, 21, 24, 28 teeth, compatible with electric bikes, mountain bikes. Suitable for 7/2 X 7/21 speed cassette.Specification:Item Type: Bike Rotating FlywheelMaterial: SteelGross Weight: 562g / 19.8ozProduct Style: 7 speed 13-28T threaded flywheelColor: SilverFits: 7/2 X 7/21 speed cassetteNumber of Teeth: 13, 15, 17, 19, 21, 24, 28 teeth.Package List:1 x Bike Flywheel