16" x 24" Aluminum Rafter Square

24" x 2" body, 16" x 1-1/2" tongue, 1/8" thick. Aluminum body will not rust. Permanently stamped graduations and numbers. Graduations measure in 1/8", 1/10", 1/12", 1/16". Includes octagon scales, rafter tables, brace tables and board foot tables.