The VERTEX TopEnd Piston Kit KTM Pro HC is designed for the high cylinder pressure found in 4-stroke engines. Crafted from forged pieces, the VERTEX piston is made from the highest quality aluminum alloy (2618) to withstand the engine's internal pressure. Each VERTEX piston features an MOS2 coating on the piston skirt to reduce wear. VERTEX is a trusted original equipment manufacturer for some of the largest motorcycle brands and is favored by many factory teams in MXGP for its performance. The VERTEX Top-End Piston Kit saves you time and money by including everything necessary for a piston replacement, such as the piston kit, cylinder gasket set, and timing chain. The 4-stroke piston options include the Pro Replica, a forged piston that matches the original design, and the Pro HC, a forged specialty piston that offers higher compression and performance enhancement.