Top End Service Kit. Complete piston assembly, gasket kit and valves to rebuild or service your bike's top end. Cost saving built into purchasing these components as a kit. Kit Includes: Piston, Rings, Clips and Pin - (2618 alloy fully CNC-machined race piston). Complete Top End Gasket Kit by Cometic™. KPMI® S.S. Black \ White Diamond® Valves, stock head diameter (all valves). Complete Dual Spring / High Performance Titanium Retainer Spring Kit. Features: Designed specifically for the performance demands of MX Bikes and Quads. Pistons designed to maintain stock compression. 2618 alloy fully CNC-machined piston with performance skirt coating. KPMI® High Performance Valvetrain is known to outlast O.E.M. by twice the service life.