SPI, SM-09146, 2 Piston Kits Ski-Doo MXZX 440 L/C 453cc Engine Type 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 Pistons are for standard bore size 65.00mm All SPI pistons, rings, pins, & circlips are manufactured to OEM specifications