SPI, 09-772, Two Piston Kits Ski-Doo 583cc Snowmobiles Included is two piston kits (pistons, rings, circlips and wrist pins) Manufactured by SPI T-Moly series pistons feature silicone aluminum alloy construction with teflon and molybdenum coating and a hard anodized crown Manufactured to OEM Specifications All kits are interchangeable with OEM components Works in both cast and chrome cylinders