Easily replace your old pump with a pump made ready. Simply remove your old pump and slide this pmr onto the shaft of your gas engine. This pump made ready consists of the pump, a VRT3-310EZ adjustable pressure actuated unloader with a built-in easy start valve, a thermal relief valve to help prevent overheating, along with an inlet filter. All fittings are quick connected. Maximum Volume: 4.0 GPM Maximum Discharge Pressure: 4000 PSI Maximum Pump Speed: 3400 RPM Bore: 13mm Stroke: 13mm Crankcase Oil Capacity: 14 oz Maximum Fluid Temperature: 165 F Inlet Port Thread: 1/2" FPT Discharge Port Thread: 3/8" FPT Hollow Shaft I.D: 1" Weight: 20 lbs Dimensions: 8.8"x9.7"x6.5"