Hello there. I have never had to do this before but here we go. I am disabled and on suplemental oxygen and numerous meds for CHF, COPD, and 4 different inhalers. I had read my RX labels and noticed that Several of them had the same "side affects"and asked my primary care Dr. and my pulmonoligist both said I needed to be on 02 all the time but I can't physically deal with the 25lb bottles I have to have strapped to my back or pull cart with bigger bottles I have to fight or get help with. This concentrator only weighs 3 lbs. Sorry Medicare won't pay for it and Humana either! Please help if you can so my latter years (hopefully several) don't have to be only at home.