temp out of stock .50mm/.020"__(2D) THIS PISTON KIT WILL FIT ALL Z50'S THRU 1981. MAKE SURE YOU KNOW WHAT SIZE OF PISTON KIT YOU NEED, BEFORE YOU ORDER!! we do have a 70cc cylinder kit if you need a bigger piston. ALL OEM PARTS , PISTON , RING SET, PIN AND BOTH CLIPS (13A/15D/2D+++)PISTON_KIT_SIZE: STD__(13A)OR(276H).25mm/.010"__(15D)