W11 Home health oxygen generator 7L adjustable large flow Up to 93% oxygen concentration Low noise and mute design,quiet and comfortable . Whether it s a quiet afternoon or a sleepy night ,It all works silently and gives you a comfortable experience. High-performance compressors provide surging power ,One-button start , fast oxygen production without waiting . Intelligent voice broadcastin Intelligent and humanized voice broadcasting ,Broadcast every operation in real time . Remote control