The nicely compact Big Skinny Metro bi-fold wallet features two ID pockets with clear windows that's great for those with multiple IDs or transit cards. This version of the Metro Bi-Fold features an exterior constructed of top grain cowhide leather and an interior made of Big Skinny's ultra-thin nylon microfiber material to help keep it thinner than a typical wallet. The Metro Bi-Fold holds up to 20 plastic cards in its two extra-wide credit card pockets as well as the clear ID pockets and it also features a billfold area for storing cash or receipts. The extra-wide pockets are lined with a rubbery coating to prevent cards from slipping out. The Metro bi-fold wallet measures 3-1/2 x 4-1/16 Inch (and 4 mm thin when empty). The first Big Skinny wallet was designed by Kiril Stefan Alexandrov (the company's founder) because he loathed sitting on a thick, heavy leather wallet. Since creating the original Sport Wallet in 2005 using an advanced nylon micro-fiber material (5 to 7 times thinner than leather), Big Skinny has added dozens of slim wallet styles for men and women with more on the way.