Topeak's MTX TrunkBag DX boasts an expandable main compartment to carry all the gear you need. It's built to last with rigid molded panels mated to 420-denier nylon. And, it's packed with handy features, such as a shoulder strap, carrying handle, taillight clip and top elastic straps. There are even reflective strips for safety. And, Topeak's ingenious MTX System makes it a snap to attach it to your Topeak MTX QuickTrack rack (sold separately).