Description: Mini Float switch in water tank is Normal ON/OFF Package Include: 1 small bag =25pcs Specification: 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, or what ever your project may be Contains no mercury Contract rating(Max):10W