This freewheel is made of high quality steel, high strength, anti-rust, non-deformation, wear-resistant and durable 2. Hollow out design reduces much weight to lessen the burden of long time cycling 3. It can promise smooth rotation of chain, suitable for chain ring 4. Designed for 8speed bike, suitable for Shimano, 5. Easy to install and use Specification: Features: This freewheel is made of high quality steel, high strength, anti-rust, non-deformation, wear-resistant and durable. Hollow out design reduces much weight to lessen the burden of long time cycling. It can promise smooth rotation of chain, suitable for chain ring. Designed for 8speed bike, suitable for Shimano, . Easy to install and use.