BTS 7 Litre 300 Bar DIN Steel Cylinder Twin Set with Boot & None Isolating Manifold S16116655 7 Litre ECS - Eurocylinder 300 Bar Steel White Steel Cylinder Twin Set complete with Twin Boot & 300 Bar G5/8 DIN Outlet Twin Manifold with no Central Isolation Valve for use with Regulator 1st Stages with Male 300 Bar DIN Thread. For use with normal Breathing Air, all O-Rings are Viton ready for O2 cleaning for use with Nitrox. Each Cylinder Measures 615mm in length with a Diameter of 140mm, weighs 12.54 Kgs plus Valve, buoyancy of -3.68 Kgs in Sea Water & -4.46 Kgs in Fresh Water when Fully Charged.