Rule Electronic Sensing Automatic Bilge Pumps deliver dependable performance with a "smart" design.These pumps boast "smart" operation, with an internal computer chip that cycles them on every 2 1/2 minutes, then quickly shuts them down if no water is detected. Capacity is rated at an honest 12V rather than 13.6V, which means that you get the capacity you are paying for in real world pumping situations. Convenient features include bases that detach to make clearing debris easy and screw-on ports that ease installation. Pumps are completely submersible, rustproof, corrosion-proof and ignition-protected. Three-way wiring enables connection to a switch for manual override or indicator light.Key FeaturesImpellers optimized to provide greater flow at the same amperageBuilt-in Thermal Cut-Off (TCO) provides added protection for pump and vesselBack flow prevention reduces the amount of water left over in the bilgeHidden air vents in the body helps prevent air locksThreaded discharge for easier installation and maintenanceInternal computer chip cycles pumps on and shuts pump off if no water detectedBuilt-in strainer bases snap off to make cleaning easyCompletely submersible, rustproof, corrosion-proof and ignition-protectedThree-way wiring enables connection to a switch for manual override or indicator lightRated flow is at 12V vs. 13.6V