I finally qualified for an 02 Easy Pulse Converver. They are very small tanks of oxygen that only releases oxygen when you breath in. I have a carrying case for it and I just wear it on my shoulder, which gave me so much more freedom when leaving the house to go to the store. Next week, after I order 12 small tanks, I am going for a walk everyday weather permitting. I need to be on 4 liters while exercising and may need to go to the level 2 of continuous oxygen if I feel really short of breath. I carry the larger tanks for when I drive and breathing emergencies. My bedroom looks like a hospital room, oxygen concentrator, 2 different size tanks of oxygen, 2 hepa air cleaners, my CPAP machine, gallons of distilled water, all of my insulin and my glucose meter and strips and syringes. Oh well, I am very thankful for being able to afford these things!.