The VERTEX Piston Kit KTM Pro Replica is designed to endure the higher cylinder pressures produced by 4-stroke engines. These pistons are forged from premium aluminum alloy (2618) to withstand the internal pressures of these high-performance engines. Each VERTEX piston is coated with MOS2 on the piston skirt to reduce wear and tear. VERTEX is an original equipment manufacturer for some of the biggest motorcycle manufacturers, and many factory teams in MXGP rely on VERTEX for their unmatched performance. The kit includes a piston, piston ring(s), piston pin, and piston pin circlip. For 4-stroke configurations, the Pro Replica pistons are forged to the original specs, while the Pro HC pistons are specially forged for higher compression and enhanced performance.