The Starrett 3020 Toolmakers\u0027 Grade Stainless Steel Square is high quality, is not graduated and offers squareness accuracy to 0.005mm (.0002" ) for every 150mm (6"). It features hardened, ground and lapped stainless steel construction on both the blade and the beam. The beam is machined at the inner corner for clearance of burr or dirt. Packed one in a plastic case. 300mm (12") square and set of 4 squares shipped in box with fitted foam insert. Wood cases as listed may be purchased separately. 75mm (2-31/32") Blade; 50mm (1-31/32") Beam, W/Plastic Case.