Bunko Box
This box is to protect index cards from humidity. I used to put all index cards stock on my desktop. But soon I found the index cards get warped by the humidity.
I found this box at 100 yen shop. It is originaly for Bunko Books (pocket edition paperback) and/or Manga Comic. It holds 12 packs of index cards.
情報カードは湿気を吸うと反ります。湿気よけのために箱に入れておきます。