The Ortlieb Back-Roller Design Pannier is the very same as the Classic Pannier, except fun prints set your bicycle apart from the rest. Its treated fabric and roll-top design protects against watery splashes, dusty trails, abrasion, and tearing. Ortlieb's QL2. 1 system lets you mount and release the pannier with a simple pull of a handle. The pannier automatically locks onto the rack the moment you mount it; it's compatible with 16mm racks, but Ortlieb includes hook inserts to fit 8, 10, and 12mm racks as well. The QL2. 1 system also features a semi-elliptical hook at the bottom that you can adjust and rotate to fit your rack so the pannier doesn't bounce as much as regular panniers.