Whale's electric bilge switch features an electric field sensor that senses water level and automatically controls a 12 or 24-volt DC bilge pump. Switch turns on when it senses a 2" water level and turns off when water is below 1/2". Innovative solid-state switch has no moving parts to wear out or seals to leak. All components are sealed and protected from exposure to solvents or corrosion. Environmentally safe unit contains no mercury. Mounting options include bulkhead, deck, or stringer mount. One-year warranty. Specifications:• Nominal Voltage: 12 or 24-volt DC• Maximum Current Draw: 20 Amps Solid construction has no moving parts Sealed components are protected from corrosion