(Used only once for 72 hours, the device is extremely clean and new in its box) * Yuwell Oxygen Generator (F7-5) 5L * Power: AC 220V at 50Hz 500VA * Oxygen Flow Rate: 0.5 - 5.0 L/min * Oxygen Concentration: 95.5% - 87% * Output Pressure: 40-70 kPa * Operating Noise: 53 dB * Weight: 27 kg * Features * Oxygen Concentrator Low Alarm * Pressure Swing Failure Alarm * Power Failure Alarm * Compressor Failure Alarm * Oxygen Concentrator (F7-5) Includes: * 1 × Humidifier Bottle (on the device itself) * 2 Filter Papers (one on the device and another extra)