Portable medical oxygen cylinders design and manufacture by NET, are produced through advanced technology. Comparing with conventional respirators, we use aluminum or aluminum composite cylinders instead of steel ones, with weight reduction of 40%-70%. More preferable for people with breathing problems. Full specifications meet different customers' demands. Working pressure: 150bar-200bar. Valves, fittings and threads according to customer's requirements. Please google 'NETCYLINDER' to find our web for more information.