The Starrett 12" Combination Set with Square, Center and Reversible Protractor Head and Blade features reversible lock bolts, scriber, spirit level in both square head and protractor head, direct reading double 180º protractor scale, hardened steel, photo-engraved blade. The combination set with square also includes a cast iron head with black wrinkle finish. Also available with satin chrome blade and protractor head. 12”, 4R Grad