Manufactured by Namura HyperDryve Series piston Kit Includes piston, rings, pin, clips you get exactly what is pictured The HyperDryve line of pistons is composed of a space-age hypereutectic aluminum alloy developed by NASA. Engineered to maintain its high tensile strength up to 700 F 370 C , 50% higher than a conventional cast piston, this gives HyperDryve pistons the strength to perform under operating conditions normally reserved for forged pistons. Piston skirts are Molybdenium Teflon coated to minimize resistance/wear and provide extended life. Also allows for smoother start-ups break-ins. Piston dome is anodized for superior heat resistance and longer lifespan Kit is for standard bore size 95.00mm Size A piston is 94.96mm 12.5 1 Compression ratio Made in Taiwan Fits 2003 Yamaha WR450F 2003 Yamaha YZ450F 2004 Yamaha WR450F 2004 Yamaha YZ450F 2005 Yamaha WR450F 2005 Yamaha YZ450F 2006 Yamaha WR450F 2006 Yamaha YZ450F 2007 Yamaha WR450F 2007 Yamaha YZ450F 2008 Yamaha WR450F 2008 Yamaha YZ450F 2009 Yamaha WR450F 2009 Yamaha YZ450F 2011 Yamaha WR450F 2012 Yamaha WR450F 2013 Yamaha WR450F 2014 Yamaha WR450F