I recently had a new oxygen assessment which shows I need 4 lpm continuous flow while walking or exerting myself. I use 2lpm at night and don't need any when sitting. I will be travelling at Christmas so can't take liquid oxygen - I usually rent a Sequal to take with me but now that I need to use oxygen when doing any walking, I am looking at portable concentrators to purchase, but don't see any that offer what I need. The respiratory tech said to use 5lpm on the pulse tank I currently use that I fill with the concentrator at home. I can't even seem to find many personal reviews on concentrators so any suggestions are welcomed.