BTS 1 Litre 200 Bar Steel Cylinder with Inert Gas Valve S16116679 1 Litre  ECS - Eurocylinder 230 Bar Steel Cylinder with DIN Valve, 1st Stage, OPV & Backplate Mounting Straps Complete Package. Cylinder compete with W21.8 Inert Gas Valve. Cylinder with Male W21.8 Inert Gas Outlet Valve for use with Inert Gases such as Argon used for Dry Suit Inflation to provide additional warmth. For use with Regulator 1st Stages with a Female W21.8 Attachment Thread. Cylinder Measures 265mm in length with a Diameter of 83mm, weighs 1.94 Kgs plus Valve & Backplate Straps, buoyancy of -0.85 Kgs in Sea Water & -0.96 Kgs in Fresh Water when Fully Charged.