Using the float principle, the water level controls the inlet and outlet water switch to achieve a constant water level effect, keep enough water and always keep the water clean. Always floats in the water when the water rises, the floats follow the rise. And the rod driven by the rise will also rise. Large water flow, high efficiency, good sealing. Works great for water trough, humidifier, fountain, aquarium, pond, chicken/dog/horse/livestock waterer, etc. The rubber washer ensures a leak-proof and spill-proof set, and you can adjust the float arm easily. Item Descriptions:< /p> Using the principle of float, the water level controls the inlet and outlet water switch, so as to achieve a constant water supply with level effect, keep enough water and always clean water. Always floats in the water, When the water rises, the floats follow the rise. And the rod driven by the rise also rises. Large water flow, high efficiency, good sealing. Works great for water trough, humidifier,