Brand New Top End Engine Rebuild Kit. Includes (2) ProX pistons, rings, wrist pins, circlips, wrist pin needle bearings, and a high quality SPI top end gasket kit. Pistons are for the standard bore (81mm).High-quality cast piston made with dedicated tooling and molding. Made from hypereutectic alloy for extra strength and reduced expansion. Full MOS2 skirt coating for improved breaking in and resistance to scuffing. Anodized piston dome for increased protection against excessive heat. Usage of high-quality rings for optimum heat transfer and sealing.