The VERTEX Race Evolution Piston is specifically developed for racing applications and stands as the ultimate performance weapon among all pistons. VERTEX 2-stroke pistons are gravity cast from an aluminum alloy with an 18% silicon content. Due to the silicon, thermal expansion at operating temperature is reduced. This advantage makes the piston less prone to rattling and fracture damage. Silicon also gives the pistons better wear properties, thereby extending the piston life. The TopEnd Piston Kits from VERTEX include everything necessary for a piston replacement (piston, piston rings, piston pin bearing, circlips, etc.). VERTEX is an OEM supplier for some of the largest motorcycle manufacturers, and many factory teams in MXGP trust the performance of VERTEX.