Johnson Aqua Jet Water Pressure Pump 12V Quiet and pulsation-free even at low speeds, the new Aqua Jet five-chamber diaphragm pump provides the perfect water pressure solution for both small and medium sized leisure and commercial boats. Features an inlet strainer that protects the pump from harmful intrusions. Whisper quiet operation Five-chamber construction Self-priming Easy, low cost maintenance Pressure cut off at 41 PSI Long service life Diaphragm Santoprene Valves EPDM Body Thermoplastic