VERTEX 2-stroke pistons are gravity cast from an aluminum alloy with an 18% silicon content. The silicon helps reduce thermal expansion at operating temperature. This advantage makes the piston less prone to knocking and fracturing. Additionally, silicon provides better wear resistance, thus extending the piston’s lifespan. The delivery includes the piston, piston ring(s), piston pin, and piston pin retaining clips! Piston versions for 2-stroke: Replica = piston corresponds to the original form, Race = performance-enhancing piston version, Pro Race = forged special piston.