VERTEX 2-stroke pistons are gravity-cast from an aluminum alloy containing 18% silicon. The inclusion of silicon reduces thermal expansion at operating temperatures, making the piston less prone to noise and crack damage. Silicon also improves the wear characteristics of the pistons, extending their lifespan. The piston kit includes piston rings, piston pin, and piston pin clips. VERTEX offers different piston versions for 2-stroke engines: Replica (original shape), Race (performance-boosting design), and Pro Race (forged specialty piston).