The VERTEX Top-End Piston Kit for Honda Pro Replica is designed to handle the increased cylinder pressure generated by 4-stroke engines. Crafted from high-quality forged aluminum alloy (2618), these pistons are built to withstand the internal pressure of the motor. Each VERTEX piston features a MOS2 coating on the piston skirt to reduce wear. VERTEX is an original equipment manufacturer for some of the largest motorcycle manufacturers, and many factory teams in the MXGP rely on VERTEX performance. The VERTEX Top-End Piston Kit saves you time and money by including everything you need for a piston replacement. The kit includes a piston set, cylinder gasket set, and timing chain. The 4-stroke piston options include the Pro Replica (forged piston matching the original form) and Pro HC (forged specialized piston with higher compression and performance enhancement).