Johnson Ultima Automatic Bilge Pump SwitchThe Johnson Ultima Switch uses the patented Mirus field effect detector cells, producing micro-electrical fields that detect disruptions caused by water and fluids. The detector cells are totally sealed and are never in contact with the water, will not corrode, and are not affected by oil for foreign debris. Johnson Ultima Switch activates at a 2" fluid level and deactivates at a 3/4" fluid level. An eight second delay prevents false starts.The Ultima Switch is rated to handle bilge pumps up to 20A, at 12V or 24V. No moving parts; Totally sealed solid state electronics and field detectors; No mercury; No exposed sensors eliminate corrosion possibilities; Unique 3-way switch disables piezo alarm while keeping warning LED lit; Environmentally sensitive; Click to Download Johnson Ultima Auto Switch Manual