Metal valve is made of chromium-plated copper alloy with 5mm connector. The connector not only uses to fill or release gas sample but also is on-off valve. When turn the connector counterclockwise, it moves up, the valve is open; the valve is closed when it moves down. The connector should move up rapidly to prevent leaking since the distance of movement is very short. The metal valve can be used in collecting or storing non-corrosive inorganic and organic gases.