Thanks for all of the advice! My vest is the old, really heavy one, so I won't be able to take that. I do have an acapella that will be coming with me. My compressor is a Pari Dura Neb 3000 Portable system (like 7 years old). How will I know if it will work there? I am trying to get a Pari Trek S, and my dr office should be calling it in for me on Monday. Will that work? Do you wear a face mask on the plane? And I'm traveling to Rome for 8 nights.