Laura, I'm the father of a 47 year old male with CF and is why I browse thru the forums. I also happen to have a bad lung problem, brought on by 40 years of smoking. As a result, I have been on O2 for 7 years now. My biggest problems have been: 1. Duration. As I recall, the larger gas bottles that you pulled, lasted about 5 hours (at 2 ltrs/hr). The smaller more portable gas bottles lasted about 3 hours. After complaining enough to my doctor and the O2 providers, I was put on liquid O2 for portable use. I have a concentrator in the house that I use for sleeping, reading, watching TV, etc. I also have a large liquid storage tank that is filled every 3 weeks. I have a small liquid portable (Helious) that I fill myself from the large tank. At 2 ltrs/hr, one fill will last me about 10 hours. The portable can be carried by a belt or by a sling over the shoulder. It weighs 3-5 pounds depending upon how much liquid O2 is still in it. 2. What use to be another major problem for me was the airlines. I HAVE to have O2 in flight! Some airlines will provide gas bottles in flight for your use. At $100/leg. I lived in Virginia and my son is near Houston, TX and at first using Delta, I had to go thru Atlanta (changed planes there). So, the cost for a round trip flight to visit my son was $400 plus the price of the ticket. For many years my wife and I have visited my son 2-4 times each. Eventually, I found out that Continental had non stop flights, so the cost of O2 dropped to $200. Within the last couple years, the FAA and the airlines have approved the use of certain portables by their passengers. One portable that is approved is the Inogen One. However, I was never able to find a provider that carried it and that I could use. This particular problem ceased for me, when my wife and I moved to Texas this past April. My son is trying to get on the transplant list and we felt we had to be closer. I'm sure like most kids with CF, you were at one time in denial, worried about appearances, etc. Same with carrying O2. However, it doesn't take long to realize you need it and are much better off with it, and you forget how you might look. If the need arrises for your father, or for you for that matter, just grin a bare it and be thankful you have it to help you breath. Good luck to you and your father. Bill