I used one for approximately 4 years you have to carry all the charger cords and accessories to be able to go out for hours it works good but you have to qualify for the pulsating price of oxygen use. Carry a double battery at all times it costs extra but will make your charging time much less. Any questions I'm available to answer.

I have Innogen concentrators I have the large one and the portable one medicare pays for it It's not the newest one but it works fine the portable one comes with 1 battery and I purchased another battery from Amazon the battery life fully charged is 4 hrs It's a pulse concentrator and it's accepted on airplanes it goes up to 3L of oxygen I only wish it was continuous flow

Inogen makes both stationary and portable concentrators. The stationary concentrators are very similar to other units and Inogen does have a contract with Medicare to provide service and most insurance companies follow Medicare's lead. The POCs are lightweight, but only one produces more than the equivalent of 1LPM. If you're interested in a POC, you need to learn about them. Best source is www.pulmonarypaper.org and look for the May-June edition. Read everything Ryan Diesem writes; he's the expert in POCs.

Innogen are lightweight , but depending on how many LPM of oxygen you require may or may not produce enough oxygen . My Innogen is fine at sea-level for me but is pretty much useless at the 5,280 feet altitude where i live .

The Inogen brand is wonderful