The #42 is one of our most popular size. Made of .016 inch mill finish aluminum. Size is 2.12 inch x 3.37 inch. Made in USA. Designed for automatic embossers, and to be broken into three (3) pieces. (4).062"x.400" slots. Sold by the box of 1,000 pieces. $0.386each. Made in USA. MILSPEC NSN #9905-01-490-1831.