Features: Race – Cast piston developed with Vertex technology and race shape profile. All pistons are heat treated with a T-5 hardening and tempering cycle. All piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life. Cast piston kits are gravity cast aluminum alloy (not forged) with 18% silicone content, which produces an extremely light but very strong piston. Kits include piston, rings, wrist pin and circlips. Replacement two-stroke piston rings sold individually; four stroke piston rings sold as a set. 12° head with single ring.