1. and longlasting: Made of highquality aluminum alloy, it ensures that the flywheel is sturdy and can withstand longterm use.2. Versatile and compatible; designed to work with the same model singlespeed bicycles and street bikes, this reverse flywheel and locking ring can enhance your experience by providing a compatible upgrade for your bicycle.3. With threads, the locking ring specification is 1.29x24, ensuring a with most bicycle .4. Smooth and reliable performance: Install the flywheel clockwise on the right side and the locking ring on the right side counterclockwise. This ingenious design minimizes friction and maximizes efficiency.5. design: The flywheel weighs about 13 grams and the locking ring weighs about 11 grams, which can reduce the overall weight of the bicycle, thereby improving maneuverability and control.Weight:Flywheel: about 13g, Locking ring: about 11g.Colour:Black & RedMaterial:7075 Aluminum AlloyPackage Contents:1 * flywheel1 * locking ringOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/ 13cm.