Topeak's MTX TrunkBag DXP boasts a pop-up main compartment and expandable side panniers so it's capable of carrying plenty of gear. Plus it's built to last with rigid molded panels mated to 600-denier nylon. And, it's packed with handy features, such as a shoulder strap, carrying handle, bottle holder, taillight clip and top elastic straps. There are even reflective strips for safety. And, Topeak's Velcro straps make it a snap to attach to your rear rack (sold separately).