You wouldn't drive a minivan in a car race, so why take your typical day hiking pack on a trail run Salomon created the Agile 12 Hydration Backpack so you can run with all the gear and water you need, without feeling like there's a monkey on your back. Snug and streamlined, this pack matches the contours of your upper back and shoulders in such a way that it simply feels like an extension of your body. Stretch material allows the hip belt to flex as needed, and quick access water bottle pockets keep additional hydration just a quick reach away. Although the Agile 12 shares its P. A. C. E. fit system with the Skin Pro pack, Salomon's engineers were careful to differentiate the two by giving the Agile 12 a more traditional v shape main compartment and shoulder straps and additional storage capacity. For running, riding, or fast hiking, few packs can hold a candle to the Agile 12.