I ended up buying a small case made by Samsonite from Staples. The problem is you have to carry the machine itself, the power supply which is nearly as big as the machine, the hose (that takes up the most room), the mask, something to clean it with, there were a couple of other things which I don't think I need to take, a manual which was totally useless, plus I also stuff my meds and my blood test kit and cuff in there. It adds up. Got few looks but told all the boarding agents it was a CPAP - they all said OK and thanked me for telling them. Got a few stares from people, but also ended up having a few discussions from others about them. I am going to exchange my machine if I can for a different model, but I think I can eventually get the space freed up.