evo.com | Osprey Hydration Packs > The Osprey Duro LT Hydration Vest Pack is a lightweight running vest that disappears on your back the moment you start moving. Two front flasks and a low-profile harness keep hydration close without adding drag, and the breathable construction means you stay cool when the miles start stacking up. Built for runners going light and fast. Hydration Included Two Hydraulics(TM) 500 mL Soft Flasks with removable WingStay(TM) stabilizers keep fluids at your fingertips. Wt: 1.4 oz / 40 grams each Front Flask Pockets With Bounce-Free Patterning and Bungee Securement 360-Degree Stretch Structured Mesh Backpanel Stabilizes Carry Mesh bluesign(R) approved 100% recycled 75D polyester airmesh Main bluesign(TM) approved 85% 70D nylon (100% recycled) / 15% spandex | Osprey Duro LT Hydration Vest Pack 2026 - Small in Black | Nylon/Spandex/Polyester