Wiseco Piston Kits Yamaha YFM350 84.0 mm (4419M) - PK1020 Top End kit includes: piston, rings, wrist pin, clips, top end bearing (2 strokes), and gasket kit Each piston is built from race proven designs that are chosen by the top race teams in all forms of racing including Supercross, Motocross, GNCC, Superbike, and more PK kits from Wiseco feature a complete top end gasket kit that gives you everything you need to complete your rebuild from premium materials Dedicated forgings used for superior strength to weight ratio utilizing aerospace alloy High Performance ring kit and alloy pin included with each piston kit for extended life and sustained power