Manufactured by Namura Kit includes piston, rings, pin, clips, & top end gasket kit (you get exactly what is pictured) Namura FORGED Series piston Unique Features: Namura Forged Pistons offer dyno-proven gains in performance and durability over industry standard 4032 forged pistons. Namura's exclusive forged alloy used offers lower expansion rates, allowing for tighter build tolerances and superior tensile strength at operating temperatures. All Namura Forged pistons come with Namura's signature features: 100% CNC-machine piston domes, hard anodized domes for reduced carbon build-up and heat resistance and M0S2 coated skirts for excellent break-in protection and properties.Piston skirts are Molybdenium Teflon coated to minimize resistance/wear and provide extended life Piston dome is anodized for superior heat resistance and longer lifespan Namura gaskets use performance materials to increase durability and provide greater reliability Includes all gaskets pictured to rebuild top end Kit is for standard bore size - 77.00mm Size A piston is 76.94mm Made in Taiwan Fits: 2001 Yamaha WR250F 2001 Yamaha YZ250F 2002 Yamaha WR250F 2002 Yamaha YZ250F 2003 Yamaha WR250F 2003 Yamaha YZ250F 2004 Yamaha WR250F 2004 Yamaha YZ250F