The Big Skinny Acrobat money clip wallet achieves such a thin profile by eliminating the billfold pocket area found in standard wallets 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 pockets, 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 pockets and two extra-deep interior storage pockets. Big Skinny designs its wallets with extra-wide pockets 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 to keep the tension.) Designed with rounded corners for comfort, it's constructed of a lightweight, water resistant nylon microfiber material that is 5 to 7 times thinner and lighter than leather. 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. 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.