... in vehicle, portable oxygen concentrator oxygen generator: 40% to 70% steady oxygen outlet,easy to operate,: 70W can be used in vehicle,oxygen concentrator,oxygen generator, portable oxygen concentrator oxygen generator: 40 ... working time. Air flow volume: 1 to 3L/min Oxygen concentration: 0.5L 80%±3% 1L 70%±3% 2L 60%±3% 3L ...