The Dead Simple Card Cases are as small as it gets.
It is pretty much just one card slot, but with a nifty hole to make it easy to get the card(s) out.
Will easily fit up to three cards, but if worn a little, it could probably do some more.
Our duty also commands us to point out that this is probably the perfect party wallet.
Material: Genuine leather
Measurments: 6.5 × 9 cm