Classic style, new technology. Big Skinny's best selling behold has gotten a Tech boost with its RFID blocking liner. Stave off the bad-guys and keep your information safe. 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. Part of our hybrid series: top-grain cowhide on the exterior, ultra-thin nylon on the interior. The RFID blocking leather 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.