A minimalist full-grain leather bifold card case with two exterior ID windows, four internal card slots, and an ultra-thin 0.25-inch depth profile is an exceptionally specific and highly efficient layout for quick-access entry and front-pocket utility.
While finding an exact match that fulfills all dimensions simultaneously (precisely 4" x 3" x 0.25") can be challenging because most standard commercial wallets add interior flaps or extra thickness, the options come very close.