Features: This freewheel was used on race bikes with or without deraiuller Needed to complete that old school bm bike Suitable for Fixed Gear Bike,single speed flywheel,removable Specification: Material: Steel Color: Brown Size: as shown Gear Teeth: 16/18/20T Package included: 1 x Single Speed Freewheel Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data. Our products are made of environmentally friendly materials, safe and non-toxic, and will not cause harm to the human body. Please read the product manual carefully before purchasing, and use it correctly according to the operation steps. If you encounter any difficulties or problems during use, please contact us in time, we will solve them for you as soon as possible. Your support is the driving force for us to move forward, and we look forward to sharing your experience and experiences with us. For the quality problems or defects of the product itself, we will provide unconditional return or repair service.