20mm Standard USA Card Holder

This is a card holder for standard USA cards. The card holder is 20mm tall (18mm interior), which is ideal for up to approx. 35 sleeved cards.

For other sizes, see my:
[30mm Standard USA Card Holder](http://www.thingiverse.com/thing:970849)
[40mm Standard USA Card Holder](http://www.thingiverse.com/thing:970857)
[60mm Standard USA Card Holder](http://www.thingiverse.com/thing:970859)