Suitable for 40-41-420 roller chain- up to 13hp horsepower. Engaging speed up to be 2300 RPM. 100% Brand New and Premium Quality Warranty:1 Year Note: 1.For proper manitenance you should add 2 drops of pil to the bushing each time before riding. 2.Clutch can mount inward or outward on crankshaft. 3.Secures onto the crankshaft with a bolt, does not have set screws. 4.Chain not included. 5.Before you purchase the starter please note the right size you need(right chain to the right cluth).