oxygen concentrator 3L, 5L, 6L, 8L, 10L/min with large LCD, Realtime oxygen concentration display, Intelligent ... diagnos Professional manufacturer of oxygen concentrator in Chinaoxygen concentrator 3L, 5L, 6L, 8L, 10L/min with large LCD, Oxygen Concentration Display Red ... .08Sound Level (dBA)standard type:3, 5L/min,≤42customized type:6L/min,≤46,customized type:8L/min,10 L/min,≤50Operating Environment ...