Due to the higher cylinder pressure of 4-stroke engines, pistons are generally manufactured from forged pieces. To withstand the inner pressure of the engine, VERTEX pistons are forged from the highest quality aluminum alloy (2618). To reduce wear, each VERTEX piston has 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 rely on the performance of VERTEX. The piston kit comes with a piston ring(s), piston pin, and piston pin retaining clip. The 4-stroke piston versions include: Pro Replica - forged piston matches original shape, and Pro HC - forged special piston (higher compression and performance-enhancing). By choosing VERTEX Piston Kit HONDA Pro Replica, you ensure superior performance and durability for your 4-stroke engine. The use of high-grade materials and meticulous engineering guarantees compatibility with factory specifications and enhances your motorcycle's overall performance. Ideal for professional racers and motorcycle enthusiasts who seek reliability and top-notch quality components.