Features1MULTI SHIFT GROUP SET: Including 9 speed freewheel, hollow integrated crank, shift lever, rear derailleur, chain, tail hook and other accessories. 2STEEL PLATE: The freewheel adopts high strength steel plate and has been quenched, tempered and hardened, very sturdy. 3RUST PREVENTION: The surface is multiple layer electroplated, which is rust prevention, with drop gear design, ensuring smoother speed change. 4ALUMINUM ALLOY CRANK: The crank is made of aluminum alloy, sturdy and light, has stylish look, strong axial strength, and wide compatibility. 5DIY YOUR BIKE: This set is great for family or friends who like cycling, allowing them to DIY their own bikes and upgrade performance.SpecificationItem Type: 9 Speed GroupsetMaterial: Aluminum AlloyTeeth Number: 11-13-16-20-24-28-32-36-40TPackage List1 x 9 Speed Freewheel3 x Freewheel Accessories1 x Tail Hook1 x Tail Hook Accessory1 x Front Derailleur1 x Rear Derailleur1 x Chain2 x Chain Buckle1 x Chain Box1 x Left Crank1 x Right Crank1 x Bottom Bracket10 x Crank Accessories1 x Crankset