1This freewheel is made of high quality steel, high strength, anti-rust, non-deformation, wear-resistant and durable 2Hollow out design reduces much weight to lessen the burden of long time cycling 3It can promise smooth rotation of chain, suitable for chain ring between 11-42T 4Designed for 10 speed bike, suitable for Shimano, SRAM 5Easy to install and useFeatures: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 between 11-42T. Designed for 10 speed bike, suitable for Shimano, SRAM. Easy to install and use. Specification:Material: SteelColor: Shown as pictureApplicable for Bike Chain Ring Range: 11-42TSuitable for Shimano, SRAMSize: Approx.17 x 4.5cm / 6.69 x 1.77inWeight: Approx. 645gPackage List: 1 x Bike Freewheel Set1 x Wrench1 x Screw