VERTEX 2-stroke pistons are cast using a gravity casting process from an aluminum alloy with an 18% silicon content. The inclusion of silicon helps reduce thermal expansion at operating temperatures. This results in a piston that is less prone to knocking and breakage. Silicon also gives the pistons better wear properties, thus extending the piston’s lifespan. The kit includes the piston with piston ring(s), piston pin, and piston pin retainer. Piston variants for 2-stroke engines include: Replica (matches the original form), Race (performance-enhanced piston design), and Pro Race (forged special piston). This ensures you get the best performance and longevity for your KTM, HQV, or GASGAS bike.