BRIGGS & STRATTON 317897GS Pressure Washer Check Valve Kit restores proper water flow control for reliable pressure washer performance. This replacement check valve kit is designed to service the pump by allowing water to flow in one direction while preventing reverse flow during operation. It works by opening under water pressure and closing when flow changes direction, helping maint... http://wholetoolbox.com/briggs-stratton-317897gs-pressure-washer-check-valve-kit/317897GS.html