VERTEX 2-Stroke Pistons are cast using a gravity casting method from an aluminum alloy containing 18% silicon. The silicon content reduces thermal expansion at operating temperatures, making the piston less prone to rattling and breakage. Additionally, silicon provides better wear characteristics, thus extending the piston’s lifespan. The kit includes a piston, piston ring(s), piston pin, and circlips. 2-Stroke Piston Types: Replica = piston matches the original form, Race = performance-enhancing piston design, Pro Race = forged special piston.