The New CoralVue Electronic Auto Top-off Unit comes complete with; float switch, pump, hose, and mounting bracket. The unit uses a pump to keep a constant level in the sump. When the water level in the sump drops, switch will turn on the reservoir pump and turn it off after the sump fills up to a correct level. Specifications: - Automatically controls water levels in aquarium or sump. - Electronically built to be safe for the user and livestock. - Octopus pump included