Erie Tools 4.4 GPM 3600 PSI Triplex High Pressure Washer Pump & Gearbox - 1" Hollow Shaft Max Pressure: 3600 PSI , Flow Rate: 4.4 GPM, 1560 Input RPM with 13 HP Forged Brass manifold provides high strength and corrosion resistance Fixed rate detergent injector - Reinforced pop off valve cage - In-line water filter Gearbox Direct Drive Triplex Plunger Pump - 1" Hollow Right Hand Shaft Inlet: 3/4" - Outlet: 3/8" Quick Disconnect - Unloader: Bolt on, internal bypass pressure trap type