The STANLEY® 24 in. Premium Aluminum English Rafter Square is a convenient and easy to use measuring tool that is built to last. The markings conveniently include brace measures, octagon scale, board measures and a rafter table. The deep graduations and numbers are filled with yellow paint for superior readability in all light conditions. This tool is built with extra thick aircraft grade aluminum for durability and maintaining an accurate square, and each one is individually inspected for accuracy. The surface is treated to resist corrosion and extend the square's life and comes in a black lacquered finish. The body measures 24- by 2-inches, and the tongue measures 16- by 1-1/2-inches. The face is graduated in 1/16-inch and 1/8-inch; the back is graduated in 1/16-inch, 1/10-inch, and 1/12-inch.