Features: white hard plastic material, 2 way design. Simple design for easy use. The Aquaculture Air Valve can be connected to aquarium tubing. Use Instruction: One end of the pump tube is connected, the other end is connected regulator. To the other end of the connection pipe regulator and the other end connected to the air stone. After starting the origin, you can adjust the size of the air flow by turning the knob on top of the regulator.