Due to the higher cylinder pressure of 4-stroke engines, the VERTEX piston is generally made from forged pieces. To withstand the internal pressure of the engine, the pistons are forged from the highest quality aluminum alloy (2618). Each VERTEX piston is coated with MOS2 on the piston skirt to reduce wear. VERTEX is the original equipment manufacturer for some of the largest motorcycle manufacturers, and many factory teams in MXGP trust in VERTEX's performance. The VERTEX Top-End Piston Kit saves you time and money, as this set includes everything you need for a piston replacement. Delivery: Piston kit including cylinder gasket set and timing chain! Piston Type 4-Stroke: Pro Replica = forged piston matches original shape, Pro HC = forged special piston (higher compression and performance-enhancing). This kit is engineered to deliver top-tier performance and durability, maintaining optimal engine functionality for your KTM, HQV, and GASGAS motorcycles. Whether you're a professional racer or a passionate hobbyist, this piston kit ensures your engine runs smoothly and efficiently, giving you the edge on the track.