The convenience of external fill in a sleek bike pack. The 2L Antidote reservoir can be refilled on the fly via the quick-release flap on the front of the pack. Two external pockets for small items like keys, wallet, phone or storage for a shed layer. Stretch elastic side panels provide for expansion; twin compression straps shrink pack down when empty. Reflective back strip with tab to click on a blinker for early morning and evening safety. Hydration capacity: 70 oz / 2 L. Dimensions: 15.5 X 10 X 5.875 in / 39.5 x 25.5 x 15 cm. Materials: air mesh.