Product DescriptionSpecifications:Product Name: Air Flow Control ValveMaterial: Copper nickel platedInlet Diameter: 0.16Inch/4 mmOutlet Diameter: 0.16Inch/4 mmPackage List: 4PCSManually control the flow of vital O2 or switch an air pump "on or off".stable performance, good sealing and long service life.A perfect set of high quality accessories that allows your air pump to control the air flow as expected.