The Oxygen Concentrator Supplies Shop carries all major brands of portable oxygen concentrators, including Philips Respironics, Caire, Inogen, Invacare, and Precision Medical. Portable oxygen concentrators allow oxygen users more freedom than standard oxygen concentrators or tanks. When purchasing a portable oxygen concentrator online, make sure that it delivers the dosage setting you have been prescribed. It should also be light enough so that you are comfortable carrying it anywhere you need to go.