Designed for mountain biking, the unisex Hydrapak Reyes (5.3L) is a workhorse that can easily hit the hiking trail, too. Big enough for a small hand pump, a spare tube, tire levers, and other important quick-fix tools as well as a light mid-layer or lunch, the Reyes is big enough for a half-day ride or hike. Its hip belt and adjustable sternum strap are both removable, but they provide needed stability for bumpy mountain bike rides. Unfortunately its quick-access front shove-it pocket isn’t accessible while wearing the loaded pack, but it’s nice to have so you don’t have to dig through your pack every time you stop. As with all of Hydrapak’s packs, the Reyes comes with a reversible reservoir that has a simple slide-lock closure: think cross between a fold-top dry bag and Ziploc bag. Plus, the hose easily disconnects from the reservoir for cleaning/filling.