Thule Paramount 18L commuter backpack is a streamlined, expandable backpack made for every day use – both on and off the bike; Roll-top closure and durable, coated materials provide reliable weather protection; Access your phone easily from dedicated pocket while in riding position; Unzip side panels to expand capacity up to 50%, transitioning streamlined bag into high-capacity urban cargo hauler; Stay visible in low light with reflective accents visible from all angles