Note: No new oxygen molecules are literally 'produced' or manufactured; the larger sized nitrogen molecules are separated out as well as remaining vapor is rendered 'oxygen rich' and that is then shipped through the machine's tubing for the needy client. We also offer service and guidance for our consumers as http://oxygen-concentrator-abu-d98653.blogsidea.com/3496917/top-devilbiss-oxygen-concentrator-in-uae-secrets