The Mountain Hardwear Supernatural 40 Backpack utilizes Mountain Hardwear's unique FitLock harness and load-bearing back-panel to provide uncomparable fit and comfort during long days on the trail. Unlike other packs this size, the SuperNatural 40 has a zip-top design instead of a lid providing a sportier shape for better hiking performance. With 2450 cubic inches of space and additional mesh pockets for water bottles this should be plenty of pack for a long day or a light overnight. This pack is also hydration compatible and has a stretch mesh front pocket to stuff layers as you shed them heading up the trail.