We supply different standards and different styles of flow meters, the flow meter scale are 0-10, 0-15, 0-25L/Min, we can also make scale figures according to customers' specific requirements. The flow meter tubes have Cube, Column and Hexagonal Prism styles, the scale can be made in to blue, black, green and other colors. The main body of the regulator is made up of 100% brass, and being treated with oxidation and chromium plating. We can also use other material which is being specified by customers. Various styles and colors (transparent, milky, blue, green, etc.) of humidifiers are available for choice. Flow meters and humidifiers can be connected in different methods, and interchangeable. The flow meter has two types: one is with pressure regulator and pressure meter, being directly screwed to the oxygen cylinder connector, and the other is equipped without pressure regulator and being connected to gas outlet. For more information pls feel free to contact us. Thanks Barbara