VERTEX 2-stroke pistons are cast using the gravity casting process from an aluminum alloy containing 18% silicon. The silicon content reduces thermal expansion at operating temperatures. This has the advantage of making the piston less prone to knocking and breakage. Additionally, silicon provides better wear resistance to the piston, thereby extending its lifespan. The piston kit includes the piston, piston ring(s), piston pin, and piston pin clips. VERTEX offers multiple piston types for 2-stroke engines: Replica = piston matches the original form, Race = performance-enhancing piston design, Pro Race = forged special piston.