The new Eagle A-III packs are hydration system-compatible and have a holding pouch for the Camelbak (or your favorite hydration system) in the main pack and openings for the drinking tube. I have an older A-III pack that was not Camelbak-compatible and so I had a company that specializes in repairing and modifying outdoor equipment, Specialty Outdoors, add the pouch and opening for me. The pack's useful life has been extended and the quality of work was very good.