Waterproof pannier and backpack in one that`s features are aimed at being a comfortable backpack, not just a pannier you can wearPadded shoulder straps with chest strap and back panel with proper venting improve comfort beyond normal pannier levelsWaterproof materials with welded seams prevent any important school papers or electronics from getting wet, even in a downpourHook on system attaches to most racks quickly and easily and is covered with a Velcro flap when being wornReflective accents improve visibility and safety for late nights or early morningsSpacious main compartment with zippered interior pocket for smaller itemsHook-on10.6x6.3x17.8`1098 c.i.BlackXXX-Large (700+ c.i.)