Brand new set of heavy duty rear sprocket and compatible hub. Commonly used on Go karts, Mini bikes and ATVs. Fits live axles with 1 inch OD. 100% Brand New and Made from high quality Steel . Includes one key stock and mounting hardware. Mount Hole Distance 2-1/16'' and 2-7/8'' across.Hub bore ID is 1 inch straight across.Keyway size 1/4''OD of sprocket 8-3/4'' and ID is 2'' Go Cart Sprocket and Hub Compatible With 1" Axle ,54 Tooth for #40,41,420 Chain