Johnson Level & Tool ADS54 54-Inch Aluminum Adjust-A-Square
Heavy-duty extruded aluminum blade and head with clear (silver) anodized finish. 1/4 In. blade thickness. Screened, thermal-bonded graduations in black in 1/8ths. Precision-machined head and blade lock together for a perfect 90 degree angle.  Quickly adjusts to any angle without disassembly.  Folds flat for easy transport.