Osprey Duro 6 Men's Running Backpack - Inspired by top runners, this roomy hydration vest is great for getting started and will give you confidence on longer runs. The Osprey running backpack prioritizes comfort, it is soft and breathable. In the front there are two pockets for flasks and in the back there is a reservoir pocket, which is not part of the vest. * volume: 6 L * material: 320 GR Nylon stretch mesh * bluesign® product – protection and safety of the environment during the production process * DWR finish * 100% recycled material * dimensions: 39.5 x 43 x 13 cm * weight: 400 g * two extra elastic mesh pockets for flasks (flasks are part of the package, 1 flask with a capacity of 500 ml) * breathable back panel * four lower elastic mesh pockets on the strap * vertical front pocket for valuables or phone * zip compartment on the front panel * front adjustable snap closure * attachment for trekking poles * safety whistle * zipped pocket on the back for holding a water bag (the bag is not part of the backpack) * zipped pocket on the back * adjustment range (rib measurements): * S – 75-90 cm (29.5-35.4 inches) * M - 90-105 cm (35.4-41.3 inches) * L - 105-120 cm (41.3-47.2 inches) * Running Vest, Sports backpacks