Features:1. Mechanical Principles    This machine incorporates physical mechanism to generate and supply rich oxygen of 29+/-2% concentration by the means of vacuum pump and macromolecules.2. Application    Ambient temperature: 5~40â„¦Æ Humidity: below 90%RH3. Storage    Ambient temperature: 0~40â„¦Æ Humidity: below 80%RH4.Control Button   Caution: This appliance should be kept away from dusts and oil vapor. If the appliance is operated in an area where temperature and humidity values  are beyond required degree, or altitude is high, oxygen concentration and air flow might be affected.Technical Information:â–¶Airflow outlet: Approx 3+/-1.5L/min(standard atmospheric pressure)â–¶Concentration: 28%+/-2%( standard atmospheric pressure) â–¶Size: 260(L)X110(W)X170(H)â–¶Wight: Generating unit: adapter 2.0KGâ–¶Power Consumption: average below 32Wâ–¶Rated Voltage: AC 100-240V 50-60HZ or DC 12-15â–¶Noise: below 50dBPacking List:1 x Main Oxygen Concentrator1 x Power adapter1 x Carry Bag1 x Extender tube with vaporizer capsule1 x English Manual1 x Rechargeable Lithium Battery1 x Lithium Battery charger1 x Nasal Cannula1 x Power Cord1 x Car Charger