The Empire Magnum Fat Boy 7 in. Aluminum Rafter Square is built from a solid extrusion that resists bending, breakage and corrosion. It accurately measures distances and angles and features stamped conversion tables with clear, easily visible markings. A thick, solid edge also makes it safe for use as a saw guide. The EMPIRE 16 in. x 24 in. Framing Square (1140) is made of lightweight aluminum that will not rust or corrode after heavy job site use. The carpenter square features ARC-SCRIBE which gives users the best solution for marking radii on the job site. The aluminum framing square has permanently stamped markings at 1/8 in., 1/10 in. and 1/16 in. graduations, as well as rafter tables. This kit includes 1 rafter square and 1 framing square.