This site is sweet and I don't really know what I'm looking at? I think it's business card holders for things besides and including business cards.
It's a lot of different kinds of stationery in the form factor of a card, presumably for easier portability. For example, the top of the list has a ballpoint pen and a mechanical pencil that can be removed from the card. The third on the list has scissors, a cutter, and a paper punch.