Due to the increased cylinder pressure of 4-stroke engines, the VERTEX piston is generally made from forged billets. To withstand the internal pressure of the engine, the pistons are forged from the highest quality aluminum alloy (2618). To reduce wear, each VERTEX piston features a MOS2 coating on the piston skirt. VERTEX is an original equipment manufacturer for some of the largest motorcycle manufacturers. Many factory teams in the MXGP also trust in VERTEX’s performance. The VERTEX Top-End Piston Kit saves you time and money, as this set includes everything needed for a piston replacement. Delivery includes: Piston kit with cylinder gasket set and timing chain! Piston version 4-stroke: Pro Replica = forged piston matching the original shape, Pro HC = forged special piston (higher compression and performance-enhancing). Whether you are a professional racer or a motorcycle enthusiast, VERTEX's top-end kits offer exceptional reliability and performance. Designed to meet the demanding needs of high-performance engines, each kit ensures an optimal fit and longevity that professionals can count on.