Osprey Duro LT With Flasks Hydration Vest Ultralight Speed Built for runners who want hands-free carry in the lightest package possible, the Duro LT delivers minimalist performance without compromise. The men's-specific fit hugs your body for a bounce-free stride, while two included 500ml soft flasks keep you hydrated on fast training runs and lightweight trail days. Smart pocketing lets you access gels and essentials on the go, and the 360-degree stretch mesh back panel keeps you cool mile after mile. Features Bounce-free stability with 360-degree stretch structured mesh backpanel and dual sternum straps for a locked-in fit Two 500ml Hydraulics soft flasks included with removable Wing Stay stabilizers for hands-free hydration Smart pocketing with dual stretch food pockets, vertical-zip front pocket, and pass-thru lumbar pocket for essentials and nutrition SPECIFICATIONSIntended Use Trail Running Fit Men's-Specific Main Fabricbluesign approved 100% recycled nylon with PFC-free DWR finish Back Panel3D Spacermesh for lightweight padding and ventilation Hydration2x 500m L Hydraulics soft flasks with removable Wing Stay stabilizers (1. 4 oz / 40g each)Pockets2 extra-large stretch mesh flask pockets, dual stretch food/supplement pockets, 1 vertical-zip front pocket, pass-thru lumbar pocket Vest Weight (without flasks)S: 0. 33 lb / 149g | M: 0. 35 lb / 159g | L: 0. 37 lb / 169g SIZING - MEN'S HYDRATION VESTSSize Chest Circumference Fits S34" - 38"Small M38" - 42"Medium L42" - 46"Large | Osprey | Duro Lt With Flasks Hydration Vest | Sandy Grey | S Hydration Pack | Nylon