All piston skirts are coated with a hi-tech Molybdenum Disulphite coating for faster break-in time and increased piston life. All pistons are heat treated with a T-5 hardening and tempering cycle. Kits include piston, rings, wrist pin and circlips. As the OE supplier of two-stroke pistons to KTM, Vertex pistons has an outstanding reputation for quality and performance. Each gravity cast piston is created with only premium aluminum alloys utilizing an 12-21% silicone content. The silicon content in Vertex pistons is crucial to the quality of the piston. Silicon is critical in decreasing thermal expansion which, when an engine reaches normal operating temperatures, can change the geometry of the piston. Controlling this expansion means that a Vertex piston can be run at tighter tolerances for more power, less noise and a longer lifespan of the piston. Plus, the silicon content decreases wear on the piston skirt which also aids in the life of the piston. In addition to the silicon, each Vertex piston utilizes a unique Molybdenum Disulphide (MOS2) coating which aids in the break-in process and reduces overall wear. With the purchase of a premium quality piston, every Vertex piston kit contains a complete set of nitride coated or chrome plated piston rings, a fully case hardened wrist pin and circlips all at a competitive price.