Manufactured by Namura Kit includes piston, rings, pin, clips, wrist pin bearing top end gasket kit you get exactly what is pictured Cast piston has super-high silicone content for additional strength 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 66.40mm Size A piston is 66.35mm Compression ratio of 10.9 1 Made in Taiwan Fits 2002 Yamaha YZ250 2003 Yamaha YZ250 2004 Yamaha YZ250 2005 Yamaha YZ250 2006 Yamaha YZ250 2007 Yamaha YZ250 2008 Yamaha YZ250 2009 Yamaha YZ250 2010 Yamaha YZ250 2011 Yamaha YZ250 2012 Yamaha YZ250 2013 Yamaha YZ250 2014 Yamaha YZ250 2015 Yamaha YZ250 2016 Yamaha YZ250 2016 Yamaha YZ250X 2017 Yamaha YZ250 2017 Yamaha YZ250X