5pcs/set Aquarium Fish Tank Air Pump Check Valve One Way Non-Return Valve

ITEM NAME:5pcs/set Aquarium Fish Tank Air Pump Check Valve One Way Non-Return Valve.After the addition of the stop valve, the pump can be placed above or below the surface of the water to prevent the risk of. Each outlet needs to connect a stop valve, two-headed pump needs two stop valves, and so on.