Oberdorfer Macerator Pumps, single phase, close-coupled, bronze, self priming, rubber impeller pump with vacuum switch. Designed specifically for pumping sewage from boats to holding tanks or sewer connections. The Oberdorfer macerator pump will macerate and pump all waste and tissue normally found in marine waste systems. IT WILL NOT HANDLE HARD SOLID OBJECTS, SANITARY NAPKINS, OR RAGS.