This bicycle single-speed cassette gear is made of high-resistance stainless steel, the strength and hardness are twice that of ordinary 316 stainless steel, and it is sturdy and durable The set includes 1 flywheel, 5 tower base gaskets, and 1 flywheel cover, which is easy to use Compression piece and gasket are made of 6061 aluminum alloy, which is super-light and corrosion-resistant, maintaining strength while reducing weight Designed for single-speed fixed gear conversion of 6-bolt disc hubs, light weight will not add more burden to your bicycle The screws are made of stainless steel, anti-corrosion and anti-rust, suitable for long-term outdoor riding Specification: Material: Aluminum alloy Teeth: 15T Package Includes: 1 Piece Flywheel 1 Piece Flywheel cover 5 Pieces Tower body gaskets Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. This flywheel is compatible with 7-10 speed cassette flywheel base, please choose 7-10 chain to install the chain Note: 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.