Specifications: Switch Power(Max): 10W Switching Voltage(Max): DC 100V Switching Urrent(Max): 0.5A Max Breakdown Voltage: DC 220V Max Carry Current: 1A Max Contract Resistance: 100mΩ Service life: 1,000,000 times Operating Temperature: -10℃～+60℃ Wire Length: 400mm Features: 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 theory: One 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. Note: - It can be used to sense the level of liquid in a tank; can activate a pump, an indicator, an alarm or other device - It can be used with hydroponics, saltwater tank, freshwater tank, gardening, aquariums for power head control, pet bowls, fish tanks, filtration, heating - But must make sure your project Contains no mercury before you use it - Cable length: About 34cm - Float length: 8.7cm What's in the package: 1 x Water Level Switch