. Materials: 6061 Aluminium alloy. . Critical test for every cylinder. . Safe,lightweight, resist corrosion, perfect treatment for surface interior and exterior to ensure the gas purity and stability. . Application:Filling compressed pure gas , gas mixtures and air. The purity gases includes: Argon,Ethane,Helium,Hydrogen,Neon,Nitrogen,Oxygen , Nitrogen monoxide,Nitrous oxide etc.