Thank you. An 18-day trip... it was incredible.

The higher the setting the louder it is. I typically use it at 2, but go up to 3 if I am climbing lots of stairs or walking up a steep hill. The difference in volume between 2 and 3 is noticeable, but barely by someone more than 5' away. I guess I will say that it is more noisy than I thought it might be, but definitely less so than some others I have seen people using.

If purchasing, please note that you will still need a prescription. I bought mine directly from Inogen and used a well-written prescription from the Mayo. The prescription from my normal provider was not well written, so was rejected. Simple language skills.

You probably know that the unit comes with a cross-body bag which is great. I also bought a backpack carrier, but a third party one from a company called O2TOTES on Amazon. I used both on the trip depending on what activities were on the schedule. They also make a fanny pack carrier, but the difference in my hip and waist measurements were not enough to keep it from sliding down.