Osprey Duro 6 with Flasks is a trail running backpack with water bottles included, the best choice for long runs on the trails! The backpack, with its 6 liters available and the numerous technical features, allows you to carry everything you need with you: energy bars, water, shell, trekking poles, smartphone, house keys, maps and much more! Made of Nylon Stretch Mesh it is light and resistant. The shoulder straps are equipped with various mesh pockets to organize cargo, two large, four small and one vertical with zipper for your smartphone or valuables. The main compartment is spacious and opens with a zipper, but there is also an external mesh pocket for use on the fly and without stopping. There is also the attachment for trekking poles. There are two quick-connect adjustable / removable chest straps that allow you to find the perfect fit, making it adhere to the body as you run for maximum stability. The bottles included are two Hydraulics 500 ml Softflasks, soft lightweight resistant and with a bite cap, ideal for hydrating yourself while running. Osprey Duro 6 with Flasks trail running backpack