Gas Save Valve And Flow Meter is a type of gas-save valve attached to the gas hose between the tube and the engine. When the gas flow is opened by pressing the button on the welding gun, the initial gas burst decreases. Use a plastic flow meter for argon or CO2 to check the flow of the welding gun. The measuring pipe must be held against the gas nozzle on the welding gun. Measuring range of 5-25 liters / minute.