The Big Skinny Acrobat money clip leather wallet achieves such a thin profile by eliminating the billfold pocket area found in standard wallet. and replacing it with a metal money clip in the middle of the bi-fold wallet area. You'll be able to slip this compact bi-fold wallet in any small pocket -- shirt, front or back pants pocket, suit pocket, or even under your hat. The Acrobat can hold 20 plastic cards and it also features an ID pocket with a clear window, two credit card pocket and two extra-deep interior storage pocket. Big Skinny designs its wallet. with extra-wide pocket that are lined with a rubbery coating to prevent cards from slipping out. The spring-loaded money clip accommodates cash and receipts and it can be removed for cleaning in a washing machine. (You should periodically slide the clip out of its nylon sheath and tighten it.) This version of the Acrobat 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 Acrobat wallet measures 4-1/16 x 3 Inch (and just 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. He created the original Sport Wallet in 2005 using an advanced nylon micro-fiber material (5 to 7 times thinner than leather).