Piston Kit (GP Racer's Choice)GP Racer's Choice pistons have T-box forgings, unique dome profiles, surface treatments, and increased compression ratios to produce more power, strength, and durabilityAll pistons are heat-treated with a T-5 hardening and tempering cycleAll piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston lifeForged pistons are forged from 2618 aluminum for superior strength and durabilityKits include piston, rings, wrist pin and circlipsReplacement two-stroke piston rings sold individually; four stroke piston rings sold as a set