Wiseco 804M06640 66.40 mm 2-Stroke Off-Road Piston All Wiseco piston kits come complete with piston rings, piston pin, and circlip CNC Machined for high precision and tight tolerances Optimized piston shape and profile for top performance Forged from high silicone aerospace quality aluminum alloy Ultimate strength, durability and toughness for high performance and long life