With a vest-like fit, the Duro 1.5 helps you keep your hydration levels high. The Duro is the best fit for most men. For women, Osprey makes the Dyna. - INcluded: 1.5 liter Hydraulics LT bladder, hose and valve - Stow-on-the-go pole holders can be used on the fly, that is without a need for taking the pack off - Front stretch pocket - Stretch side pockets - Weights and measurements per size: - S: 380 g, dimensions 28 x 44 x 13 cm, for chest circumferences between 7590 cm - M: 400 g, dimensions 33 x 44 x 13 cm, for chest circumferences between 90105 cm - L: 420 g, dimensions 38 x 44 x 13 cm, for chest circumferences between 105120 cm