Features:1. Suitable for replacing the original cog or changing other specifications. 2. It is recommended to use a steel hub body, which is not easy to damage the hub body.3. Providing fast riding speed with less effort needed. Fluent turning movement without much noise.4. This bike freewheel is made of high-strength Stainless steel, sturdy, corrosion-resistant, high-performance and durable, long service life.5. The bike freewheel parts are applicable to mountain bike freewheel, not applicable to highway freewheel. There are several models to choose from and it is one of the best companions for mountain bikes.Notice:*Actual color may be slightly different from the image due to different Display and light effect*Please allow 1-3cm deviation due to manual measurementDescription:Size: 55.8mm/ 57mm/ 61.5mm/ 65.7mm/ 70.5mm/ 74.8mm/ 80.5mm Package List:1 pcs x Bike Freewheel Cog