This is a small, highly portable rigid heddle backstrap loom. Your first project can be a new backstrap, and you can use paracord, USB cable, shoelaces, or whatever you want to stand in until you have your newly woven strap.

You'll need a backstrap, an anchor strap, and yarn to use it. I've been using carabiners and paracord while I weave my new strap.

The different heddles support 19, 21, or 23 warp threads and work nicely to make straps and narrow bands. Look on YouTube for instructions on using a backstrap loom (there are a few types).

UPDATE: I've added a clamp to hold your work near your body so that you don't have to tie your woven strap in a knot to hold it. You'll need M3 x 20mm thumb screws (affiliate link: https://amzn.to/43Y8JGS) and two low-profile M4 heat-set inserts (affiliate link: https://amzn.to/3KrYzaN) to complete it. Print it in ABS (or at least PETG) to withstand the heat of melting in the inserts, and give it an extra wall for strength (3 walls will work).

I've also added a blunt version of the batten to increase the chances of getting it through airport security. The original one is rather weapon-like.