Victorinox has a reputation for standing up to challenges, and this bag upholds that tradition. It's a good, solid piece of luggage despite being collapsible. Victorinox has a variety of styles of collapsible luggage. The collapsible duffel bag is particularly useful for fitting into odd-shaped areas in the back of a van or in an overhead bin.
This bigger version of a convertible keychain backpack works as a bag as well as a backpack. They are relatively waterproof (against rain, not against immersion), very light, and remarkably durable. I've had one for eight years and it has been overstuffed, dropped, thrown, caught on doorknobs, machine washed, and generally maltreated, and it still is holding up just fine without any repairs. Only problem? An overzealous airline security person once demanded that I "open" the tiny solid pouch it folds into - and stared at me mystified as the "full" pouch ballooned into a now-empty backpack, at which he dismissively gestured me to move on. While I've had generic versions of the same thing work well, the one that is making the endurance record is a Kiva one.
True confession: I travel with two or three packable backpacks. One, usually the more expensive and/or durable one, like the one mentioned here, ends up being my outer video camera bag with enough room left over to stuff in a long-sleeved tee, a few snacks, and sunscreen. The second one is usually lent to a fellow traveler who wishes they'd brought one, and the third is just in case I permanently lose or generously give away Number One or Number Two.
While I love truly packable bags, this expandable messenger bag also has its uses and is a more stylish option than some of its collapsible kin.
While not as convenient in my opinion as a folding backpack, this item is ideal for bringing back souvenirs.