This cylinder kit includes a Cylinder Works Cylinder, Vertex Piston Kit, and your choice of Cylinder Works or Cometic gaskets. Cylinder Works Cylinder Standard bore. Stock in appearance. Precision honed. Nickel silicon carbide plated. O.E.M. quality without the O.E.M. price. Vertex Piston Kit When it comes to power and performance, Vertex four-stroke pistons are hard to beat. Forged from the highest quality 2618 aluminum alloy, Vertex pistons are perfectly suited to handle the rigors and high pressures of today's modern four-stroke engines. Plus, to aid in the break-in process and reduce wear, every Vertex piston utilizes a unique Molybdenum Disulphide (MOS2) coating on the piston skirt.