The Whale Electric Field Sensor Switch automatically activates and shuts off bilge pumps when water reaches specific levels. Its worry-free, precise operation ensures proper bilge pumping. This switch automatically activates the bilge pump when 2 inches of water is sensed, and it turns the pump off when the water level drops below ½ inch. Two color-coded wires make installation easy, and there are two test circles that can be used to ensure activation. This unit offers side or base mounting to suit the available space configuration. This switch can operate with 12V or 24V power, and it is suitable for up to 20 amps. Whale designs and manufactures reliable marine water systems which are easy to install and use; providing boating enthusiasts with water, waste management and durable bilge pumps. For over 70 years, Whale has delivered innovative, high quality products that ensure peace of mind and allow you to enjoy your adventures on the water.