Who new that finding a backpack would be so chalanging? I mean its crazy all the thought and measurements that go into the perfect fit. A couple days ago my twin and i walked into our local REI expecting to look at some backpacks and get an idea of what was needed. After we had been in there awhile we decided maybe we should ask an employee for some assistance because it turned out we had not a clue what to look at or what to look for. As soon as the guy walked over he started a half hour lecture on kinds of packs and the science behind it. all of a sudden my eyes were being opened to a whole new world and I was truly overwhelmed. The man then proceeded to measure us and help us try on a few while non stop educating us on what we are supposed to be feeling when we wear our pack. After awhile he told us he wanted to put waits in the pack and have us walk around the store for about five minutes each in two different packs, and then switch and repeat. Well we did and it was the best decision i have ever made because i walked out of that store confident in how long my back was and also what i wanted to wear on my back for nine months. I highly recommend going and getting fit for your pack before purchase because it will make a worlds of difference when you are comfortable carrying your pack across countries! You then are set up for success to order online because you will know your size and maybe some companies that you thought were comfy! Good luck with your search peeps!!