Specification: Brand new Material: plastic Switching current (Max): 0.5A Breakdown voltage (Max): 220V DC Feature Simple structure. Long service life. Easy to use. A float switch is a device used to sense the level of liquid within a tank, it may actuate a pump, an indicator, an alarm, or other device. Use them with hydroponics, saltwater tank, freshwater tank, gardening, aquariums for power head control, pet bowls, fish tanks, filtration, heating etc. Working theoryOne or more reed tubes are mounted in a closed, non-permeable tube. Then the tube is passed through one or more of the hollow and internally floating magnets. The rise or fall of the liquid level causes the floating ball to move together, thereby causing the reed switch in the non-permeable tube to be actuated to open or close and output a switching signal. Package included:1 x Water Level Switch Quantity: 1pc Note: Manual measurement, there may be 1-2cm/1-3g error, which is not a quality problem. Due to different screen displays, there may be a color difference between the real object and the picture, and the main picture shall prevail .