Manufactured by SPI Includes 2 pistons, ring sets, wrist pins, circlips as pictured SPI pistons are engineered to provide the best possible path for combustion chamber heat transfer to the cylinder walls All SPI pistons, rings, pins, circlips are manufactured to OEM specifications All individual components are interchangeable with original parts Piston weight is compatible with original piston T-Moly series with Teflon-Molybdenum coating T-Moly series pistons reduce friction, resist seizure, improve durability Made in Taiwan Pistons are for standard bore size 73.40mm Fits 2000 Arctic Cat ZL 550 ESR 2001 Arctic Cat ZL 550 ESR 2001 Arctic Cat ZL 550 2002 Arctic Cat ZL 550 2002 Arctic Cat ZL 550 ESR 2003 Arctic Cat ZL 550 2003 Arctic Cat ZL 550 ESR