Edson's manual pumps have the highest capacity discharge per stroke on the market. Built tough for years of service and are designed simple for on-board maintenance. These pumps are self priming and have a large floe-through inlet and discharge passages for virtual clog-proof operation. With the reinforced diaphragms and valves have a long life of over 3,000,000 cycles and come in 1-1/2" or 2" NPT ports. Made from marine-grade bronze or anodized aluminum Edson's pumps are made to last!