FEATURES? Complete plastic outer shell, safe and reliable. Timing accumulating function, showing total working hours through the display screen. Press safety valve help ensure better security. Power failure alarming function, high pressure and low pressure alarming function. Compressor has got heat protection that ensures the safety of the compressor and concentrator. Having nebulizing interface optional. May connect with nebulizer to have nebulizing cure. Technical data: Oxygen flow: 0.5?5L/min Oxygen concentration: 95.5%~87% Output pressure: 40~70kPa Pressure relief mechanism operational at: 250kPa±25kPa Operation noise: ?53dB(A) Input power: 500VA Minimum operating time: 30minutes The "W" behind the item name means with nebulizing function, we can adapting nebulizer function to every oxygen concentrator. Oxygen concentrator (with nebulizer function) provided by yuwell uses the combination of oxygen uptake and atomization function to offer clean and safe air. Furthermore it's a multifunctional machine that also assist in atomized treatment while maintaining the same oxygen concentration.