The flash of inspiration it took to transform a limp old piece of truck tarp into a stable, large-format travel bag that, even only half-full, wouldn’t exceed the free baggage limit imposed by the world’s airlines took its time coming. The solution Freitag’s product developers and prototype cutters hit on is as unusual as it’s compelling. Because it isn’t based on some bulky frame-like container or semi-finished shell, but actually comes from Freitag’s favorite means of transport. Hidden away inside the Zeppelin is a common-or-garden bicycle inner tube you can inflate with a standard pump and, thanks to the zip, replace quickly and simply.