Johnson 36303 Ultima Switch Produces micro-electrical fields that detect disruptions caused by water and fluids. Detector cells are never in contact with the water, will not corrode and are not affected by oil or foreign debris. Activates at a 2 fluid level and deactivates at a 3/4 fluid level. 8 second delay prevents false starts. Rated to handle pumps up to 20 amps at 12 or 24 volts.