Here is the bicolor slim credit cards holder by Lucrin. This cards case in authentic leather is delivered with a removable plastic pocket that can accommodate 6 x 2 additional cards. The leather cards case itself consists of 2 pockets for debit/credit cards and 2 really practical flat multi-function pockets.
Dimensions, closed: 4.1 x 3.0 inches
Dimensions, open: 4.1 x 5.9 inches