Owgels Oxygen Concentrator is made up of German Technology with the best-in-class product. This portable oxygen concentrator machine converts the surrounding air into pure oxygen that is ready to breathe. This machine is equipped with a humidifier bottle, oxygen hose, nebulizer and air filter. So, there is no need to bother refilling your oxygen cylinder again. It Can produce oxygen from 1 liter to 7 liters per minute at various concentration flow. Concentration of oxygen level is 90% at 1L/min. It can be used continuously. The O2 (Oxygen) produced by this concentrator machine is clean.