Product Name: Direct Drive Pressure Washer Pump,Triplex Plunger Pump The Part Number: EZ4040,EZ4040G,RRV4G40 Specifications: Direct Drive with Gas Flange 9.0-13.0 HP SAE; Max. Volume: 4.0 GPM; Max. Discharge Pressure: 4,000 PSI; Max. Pump Speed: 3400 RPM; Shaft Diameter: 1” Hollow; Max. Horsepower Requirements: 13.0 GHP; Max. Fluid Temp.: 165 degrees F.; Inlet Ports (2): 1/2" BSP; Discharge Ports (2): 3/8" BSP; Drive Side: Standard right; Forged brass head; Solid ceramic plungers;