This pack was odd for me. I purchased a medium size pack. Normally, a medium size pack fits me fairly well. I purchased medium based on the sizing information on Go-lite's web site. The pack did not fit correctly. Even when letting the shoulder straps out as far as they would go the pack fully loaded or unloaded would not allow the waist belt to rest on my hips. The buckles at the bottom of the padded shoulder harnesses were above my arm pits!!! This put the chest harness near my collar bones when adjusted to the lowest position. Nevertheless, I found that the trade off in weight would not be worth no having a well designed frame. So, I sent the pack back. The company has a very good satisfaction guarantee. A large Gregory Z55 on the way. I am hoping that this will be the ticket to comfort and a good fit.