This is a quick deck holder I made for use in a multitude of games. It's intended for the standard Magic the Gathering sized cards in card sleeves. They'll hold up to 50 sleeved cards, if the sleeves are pretty tight/flat. I tend to use them with 40 or so card decks. I printed a bunch of these and am currently using them in the following games.

Massive Darkness, Arkham Horror TCG, Lord of the Rings TCG, Star Wars Destiny, etc.