An economical workhorse, the 55 series are engineered for flexibility. The 5 chamber series are our Heavy-Duty water pump. It provides high volume water flow with reduced pump cycling, thanks to the large five-chamber diaphragm. With on-demand switch, 3.0 to 5.0 GPM, and 70 PSI, new demand switch, control of pressure precise, stable performance, low starting pressure, good heat dissipation, the 55 series will meet your special requirements with positive predictable performance. With built-in bypass function, 55 series is able to reduce rapid cycling and allow water to flow back from the outside to the inlet side of the pump. SEAFLO also offers a variety of easy connect fittings and filters.