I was skeptical of the usefulness and price of these at first. I was incorrect. These little folder-holders can be extremely useful in a variety of circumstances and for a variety of uses. To name a few: not just a coin wallet but a cash wallet if you don’t mind folding bills and you separate cash from cards, an earbud holder, an alternative to a jewelry bag for carrying earrings/etc. (or other small, somewhat delicate goods), a pill case, a protective holder for something rough that would damage other objects it’s placed next to (keys? pet rock?), etc. YMMV as to whether cases are too clumsy a solution for some of these needs, but if you get one, leather or Kydex or whatever, you’ll find it very handy.