Big Bore Gasket Kit - Yamaha Ready-to-install, direct bolt-on cylinders require no re-plating and look virtually identical to the OEM cylinders, Cylinder kits include matched Vertex pistons to ensure longevity, performance and reduced engine noise, Nickel Silicon Carbide plated for long life, Kits come complete with gaskets, cylinder, piston, rings, pin and clips, Big bore cylinders do not require machine work, Made in the U.S.A.