There are 3 types of systems available for the supply of oxygen:  Compressed Gas - this is oxygen stored under pressure in a cylinder equipped with a regulator that controls the flow rate.  Liquid Oxygen - is oxygen stored as extremely cold liquid in a vessel very much like a thermos.  The liquid converts to gas upon release and you breathe it in the same as compressed gas.  The third type of home oxygen system is the Portable Oxygen Concentrator.  An oxygen concentrator is an electrically powered device that separates oxygen from the room air, concentrates and delivers it at your prescribed rate.  This system is less expensive than liquid oxygen and eliminates the need for re-supply of oxygen cylinders. Intermedical provide four portable oxygen concentrators:

• AirSep Lifestyle Portable Oxygen Concentrator
• InogenOne Portable Oxygen Concentrator
• SeQual Eclipse Portable Oxygen Concentrator
• AirSep Freestyle Portable Oxygen Concentrator