The VERTEX 2-stroke pistons are crafted using the gravity casting method with an aluminum alloy containing 18% silicon. This silicon content helps reduce thermal expansion at operating temperatures, which in turn minimizes the risk of piston slap and potential damage. The inclusion of silicon also enhances the piston's wear resistance, thereby extending its overall lifespan. The kit includes the piston along with the piston ring(s), piston pin, and piston pin lock! VERTEX offers three variations of 2-stroke pistons: Replica (which matches the original form), Race (designed for improved performance), and Pro Race (a specially forged piston).