The VERTEX Top-End Piston Kit for YAMAHA Pro HC is designed to withstand the higher cylinder pressures of 4-stroke engines. Crafted from the finest 2618 aluminum alloy, the piston is forged to endure the internal pressure of the motor efficiently. Each VERTEX piston features a MOS2 coating on the piston skirt, significantly reducing wear and increasing longevity. VERTEX is a trusted original equipment manufacturer (OEM) for some of the largest motorcycle manufacturers. Many MXGP factory teams rely on the unparalleled performance of VERTEX pistons. The VERTEX Top-End Piston Kit is an all-inclusive set that saves you time and money by providing everything needed for piston replacement. The package includes the piston kit, cylinder gasket set, and timing chain. The 4-stroke piston is available in Pro Replica, a forged piston conforming to the original shape, and Pro HC, a forged special piston offering higher compression and performance enhancement.