Pro HC – Forged piston developed with Vertex technology and high compression All pistons are heat-treated with a T-5 hardening and tempering cycle Piston skirts are coated with a high-tech Molybdenum Disulphite coating for faster break-in time and increased piston life Forged pistons are forged from 2618 aluminum for superior strength and durability Due to the higher compression, power and torque can be improved across entire rpm range Kits include piston, rings, wrist pin and circlips Replacement two-stroke piston rings sold individually; four-stroke piston rings sold as a set