VERTEX 2-stroke pistons are gravity-cast from an aluminum alloy containing 18% silicon. The silicon reduces thermal expansion at operating temperature, which means the piston is less prone to rattling and breakage. Additionally, silicon enhances the pistons' wear characteristics, thereby extending their lifespan. The piston kit includes pistons, piston rings, piston pins, and piston pin clips. Piston versions for 2-stroke engines come in three types: Replica, which matches the original form; Race, which is engineered for performance enhancement; and Pro Race, which is a forged specialty piston.