" Made of high-quality, soft and naturally grained leather, the Porsche Design Business Collection attracts through timeless looks and durability. Stitched edges, a stamped Porsche Design logo and the characteristic V-line as a design detail subtly convey the exclusive craftsmanship behind the series. The Porsche Design Business Billfold 13 is distinguished by its extraordinarily organized, spacious interior. 13 credit card slots, a compartment for bills with a zipper, two mesh pockets for ID..