Like a suit of armor, the Big Skinny RFID blocking slimline bi-fold wallet is a feat of design. Our proprietary nylon Micro fiber keeps this wallet thin and a layer of RFID blocking material inside the wallet protects you from would-be identity thieves. This machine-washable nylon bi-fold is one versatile, sporty wallet. Full-sized billfold area and card pockets are lined with non-slip interior to prevent cards/cash from falling out. Capacity: about 20-25 plastic cards plus cash. Designed with rounded corners for comfort, it's constructed of a lightweight, water resistant nylon Micro fiber material that is 5 to 7 times thinner and lighter than leather. It's machine washable for easy care, and it dries out in about 20 minutes. The RFID blocking slimline bi-fold wallet measures 4-1/2 x 3-3/8 inches (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.