The convenience of external fill in a sleek bike pack. The 2L 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.