Jabsco-Rule 500 GPH Standard 12V Bilge Pump With over 50 years of excellence Jabsco-Rule provides superb pumping performance. Helps keep your bilge clear of water. Going through rigorous engineering and testing bring flow efficiency in even the toughest conditions. Threaded Discharge - provides easy install and maintenance Back Flow Prevention - reduces odor and helps keep bilge clean by reducing leftover water in the bilge High Flow - provides better flow at consistent amperage through impeller