VERTEX 2-stroke pistons are created using gravity casting from an aluminum alloy with an 18% silicon content. The silicon helps reduce thermal expansion at operating temperatures, resulting in a piston that is less prone to knocking and fractures. Additionally, silicon imparts better wear resistance to the pistons, thus extending their lifespan. The kit includes the piston, piston ring(s), piston pin, and piston pin clips. Piston types available for 2-strokes: Replica (matches original form), Race (performance-enhanced), and Pro Race (forged specialty piston).