Description:Constructed of nickel chromium steel materials, anti-rust, non-deformation, wear-resistant, high performance of durability.The -sliding sprocket features tooth profile with contoured shifting gates for clear and smooth shifting even under load.Mountain Bike Road Bicycle flywheel, hollow design, super high strength, chain slot and mud hole design, light weight, easy to clean.Suitable for mountain road bicycle flywheel, bicycle maintenance, modification, etcHigh-performance gear combinations provide wonderful riding experience!Specification:Material: Nickel Chromium SteelPackage Includes:1 Piece Bicycle FreewheelNote: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. Wish you a wonderful on-line shopping!