Description: Model: 18 tooth freewheel for bike Function: mainly used to refit your bike Strong affordability and flexible rotation Easy to install and dismantle Idea for recreational vehicle,children carriages,electric motor car,ect. Specification: Color: copper Material: metal Outside diameter:76mm/2.99 inch Thickness: 25.4mm/0.57 inch Internal thread: about 34 ± 0.05mm Whether it can be rotated reversely: No Package Includes: 1 x Bicycle 18T Tooth Freewheel Sprocket Gear