The solid-state electronic automatic switch Ultima Switch uses the patented Mirus field effect detector cells producing micro-electrical fields that detect disruptions caused by water and fluids. Detector cells are totally sealed and are never in contact with the water, will not corrode and are not affected by oil or foreign debris.• Compatibility: SPX FLOW Johnson Pump Cartridge Bilge Pumps• Voltage Rating: 12 Volt• With Wiring Harness: No• With Fuse Holder: No• Ultima Switch Is Rated To Handle Pumps Up To 20 Ampere No Exposed Sensors Eliminate Corrosion Possibilities Activates At A 50 Millimeter Fluid Level And Deactivates At A 20 Millimeter Fluid Level Three Second Delay Prevents False Starts From Water Sloshing In The Bilge | Bilge Pump Switch, Electronic Automatic Switch; 20 Amp