The VERTEX Race Evolution Piston is specifically engineered for racing applications, making it the ultimate performance weapon among all pistons. VERTEX 2-stroke pistons are cast using a gravity casting process from an aluminum alloy with 18% silicon content. The silicon reduces thermal expansion at operating temperatures, which has the advantage of making the piston less susceptible to rattling and fracture damage. Additionally, silicon imparts better wear characteristics to the pistons, thus extending the piston’s lifespan. The TopEnd Piston Kits from VERTEX include everything needed for a piston replacement: piston, piston rings, piston pin bearing, circlips, etc. VERTEX is an original equipment manufacturer (OEM) for some of the largest motorcycle manufacturers and is trusted by many factory teams in the MXGP for their performance.