I’ve been overnight backpacking for about 25 years, and last July was the first time I’d been four days on the trail without experiencing shoulder and neck pain caused by my pack. I was also carrying more weight than ever before. I’m convinced it was no coincidence I was wearing my new Osprey Aura 50. What makes the Osprey Aura better than my previous packs? For starters, the ability to custom fit the pack through its adjustable harness and ‘fit-on-the-fly’ hip belt.