VERTEX 2-stroke pistons are gravity cast from an aluminum alloy with 18% silicon content. The inclusion of silicon reduces thermal expansion at operating temperatures. This results in the piston being less prone to rattling and fracture damage. Additionally, silicon imparts better wear characteristics to the pistons, thereby prolonging their service life. The piston kit includes the piston ring(s), piston pin, and piston pin circlip. Piston variants for 2-stroke engines include: Replica (piston matches the original form), Race (performance-enhancing piston design), and Pro Race (special forged piston).