Kimpex OEM style piston kits include piston, rings, pin and circlips. Engineered to provide the best possible path for combustion chamber heat transfer to the cylinder walls. All pistons, rings, pins and circlips are manufactured to OEM specs. All individual components are interchangeable with original parts. Piston weights are also compatible with original pistons. Note: The arrow on top of Kimpex pistons should point towards the exhaust side of the engine (except on Polaris pistons, where the arrow points to the magneto side.)