3.0 GPM. 12V With 55 PSI Sealed Shut-Off Switch. Corrosion Resistant Electro Coated Motor. Thermally Protected. Ignition Protected, CE. Self Priming up to 6'. SHURFLO's 4138 fresh water pump design was created with a unique over-molded single-piece diaphragm and internal by-pass, assuring long life and top performance in all plumbing systems. Designed as the next legendary pump to exceed the expectations of our customers, the 4138 pump is constructed for smooth flow and no rapid cycling. The 4138 fresh water automatic demand pump is quiet, thermally protected and can run dry without damage.