Polaris Piston & Ring Set 650 SL 650 1992 1993 1994 1995 Please select the piston size in the drop down menu next to the picture SBT offers the first jet ski piston to be sold with a LIFETIME WARRANTY against defect. Our pistons are cast using a high-silicone-content aluminum Our "standard" pistons are comparable to others' "premium" pistons - anodized on the top surface for better heat resistance and surface strength, graphite coated on the sides to reduce friction between the piston and cylinder and enable efficient break in SBT's rings are made of chromium-plated ductile iron and are included along with all new wrist-pins and c-clips The piston and ring sets are available in an assortment of sizes to accommodate your needs