Can be used to detect the level of liquid in a tank, easy to use. A float switch is a device used to detect the level of liquid in a tank, it can operate a pump, indicator, alarm or other device. Use them with hydroponics, saltwater tank, freshwater tank, gardening, aquariums for power head control, pet bowls, aquariums, filtration, heating, etc. This liquid float switch can be installed as a normally closed/normally open switch according to your needs. Switching voltage (max): 100V DC; Switching current (max): 0.5A