VERTEX 2-stroke pistons are cast by gravity from an aluminum alloy with an 18% silicon content. Silicon helps reduce thermal expansion at operating temperatures, making the piston less prone to knocking and fractures. Additionally, silicon enhances the piston's wear characteristics, thereby extending its lifespan. The piston kit includes the piston, piston ring(s), piston pin, and piston pin clips. Piston options for 2-stroke engines: Replica, which matches the original shape; Race, which offers performance enhancements; and Pro Race, which features a forged special piston.