Johnson Pump 4.0 Aqua Jet PumpThese 5 chamber diaphragm pumps feature dramatically lower noise and water pulsation compared to 3 or 4 chamber designs. They are self priming to 6. 5' (8. 2' for 5. 2 gpm model), have an integrated pressure switch and can run dry without damage. Use an inlet strainer before pump intake. Accumulator tanks are recommended. Connections for 3 8" NPT, 1 2" hose and 1 2" NPT, 3 4" hose. Volts : 12 GPM : 4