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). To reduce wear, every VERTEX piston features a MOS2 coating on the piston skirt. VERTEX is an original equipment manufacturer for some of the largest motorcycle manufacturers and many factory teams in the MXGP trust the performance of VERTEX. The VERTEX Top-End Piston Kit saves you time and money, as this set includes everything needed for a piston change. Delivery includes: piston kit with cylinder gasket set and timing chain! 4-stroke piston design: Pro Replica = forged piston equivalent to original form, Pro HC = forged special piston (higher compression and performance-enhancing). Perfect for those looking to maintain their bike with high-quality parts, this kit ensures optimal performance, durability, and efficiency. Equip your motorcycle with the VERTEX Top-End Piston Kit and experience a new level of riding excellence.