Enhanced Pump Flow & Head: Power: 3HP, 230V; Diameter: 4' (for 4' or bigger well casing); Discharge: 1-1/4' NPT. This deep well submersible pump is designed with 18-stage thermoplastic impellers, providing 37GPM max flow and 640 ft max head. It comes with a 33 ft electric cord, making life without modern plumbing a lot easier. Pump out your worries with ease and relax. No challenge is too big for you. Upgraded Stainless Steel: The whole frame of our deep well pump is unlike anything on the market. It is made of stainless steel, including the outlet and connecting components. You don't have to worry about it becoming rusted or corroded after being underwater for a long time. With ETL certification and IP68 waterproof grade, the pump can be used for 8-10 years