BTS 1.8 Litre 230 Bar Black Steel Cylinder with Rebreather Valve S16716679 1.8 Litre 230 Bar ECS - Eurocylinder Black Steel Cylinder complete with M18 230 Bar G5/8 DIN Outlet Rebreather Valve with Viton O-Rings, for use with normal Breathing Air. Cylinder Measures 450mm in length with a Diameter of 83mm, weighs 3.2 Kgs plus Valve, buoyancy of -1.05 Kgs in Sea Water & -1.26 Kgs in Fresh Water when Fully Charged.