The water level sensor is a device that measures the liquid level in a fixed container that is too high or too low. The method of measuring the liquid level can be divided into two types: a contact type and a non-contact type. The input type water level transmitter we call is a contact measurement, which converts the height of the liquid level into an electrical signal for output.The Anti-Corrosion Water Level Sensor with Ball 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 another device. Use them in hydroponics, saltwater tank, freshwater tank, gardening, aquariums for power head control, pet bowls, fish tanks, filtration, heating, or whatever your project may be.