AirSep Focus is an extremely lightweight portable concentrator and doesn’t require refilling it with oxygen. The mobile unit weighs less than 2 pounds and is currently the lightest and smallest oxygen concentrator out today. The AirSep Focus is well known for being the smallest and most comfortable to wear portable oxygen concentrator on the market. How is the name relevant to this oxygen concentrator? You could look at it this way – you can focus on living an active and healthy lifestyle after your oxygen needs are met by such a small and easy-to-carry portable oxygen concentrator. Despite its small size, you will find that the Focus has the same excellent battery life as larger portable oxygen concentrators, and is just as dependable and robust, and is the perfect unit for travel, high altitude activities, or hikes.