Check valves are for common aquarium air pumps. Please DO NOT use with CO2 system. Great one way check valve for aquarium and fish tank. When the position of the air pump is lower than the water surface, prevent the backflow of water from damaging the front air pump or other equipment. After adding the check valve, the pump will air can be placed above the water surface or below the water body Made of durable transparent plastic. Can be used for a long time, beautiful and durable. < p>Prevent the aquarium water from flowing back into the air pump and burn the air pump to avoid danger.Wonderful accessory for aquarium air pump.
