"This Liquidynamics 12 Volt Membrane Pump is self-priming, eliminating contamination from priming. The 8 GPM flow allows it to be used with automatic nozzles. 12V DC power supply. Dimensions L x W x H in. 7 x 8 x 12, Bypass Valve Internal, Outlet Port in. 3/4, Seal Type EPDM, Self-Priming Yes, Flow GPM 8, Inlet Port in. 3/4, Volts 12. DEF-compatible polypropylene construction with EPDM seals and membranes Internal bypass with maximum discharge pressure of 22 PSI 6ft.L power cord"