The oxygen concentrator is a device the extracts oxygen from atmospheric air.It will typically be an electrically-powered molecular sieve (artificial zeolite) used to separate nitrogen from ambient air.It could be applied widely in the hospitals at all different level clinics,health centers and family nursing,health care for the old person,mental workers and students etc... The oxygen concentrator can supply 1-2 patients simultaneously,with steady oxygen flowing out,safe and reliable,low cost,adjustable flow Indicating Lamp: 1) P.O.: Power switch (green lamp):If oxygen machine is connected with electricity it will be green 2) P.F.: Power failure(red lamp):It means power failure alarm, when no electricity