Tested to the highest standard, achieving rated performance at 12V, resulting in higher flow with better efficiency for the toughest applications. The RuleMate automatic bilge pump turns on automatically when water rises and switches off again when its gone. Our pumps incorporate a market leading backup feature to tell you if something in the bilge has fouled or is blocking the pump giving peace of mind to the user. RuleMate series pumps now come with check valves to minimize unwanted water in the bilge, anti-airlock vents to help maximize performance and a thermal cut out feature for added security. Automatic level sensing with back up feature, Submersible and Ignition Protected, High efficiency, low amp motor, Stainless-steel shaft, & Includes backflow preventer.