Combination Square Set, Number of Pieces 4, Blade Finish Satin, Blade Material Steel, Head Length 3 in, Head Width 9/16 in, Blade Length 12 in, Blade Thickness 0.08 in, Blade Width 3/4 in, Graduation Mark Style Etched, Graduation Marks - Front 1/100 in (Aircraft Quick Reading), 1/64 in (Quick Reading), Head Type Center/Reversible Protractor/Square, System of Measurement SAE, Head Material Steel, Includes Reversible Lock Bolt, Scriber, Spirit Level, Head Vial Included Yes, Accuracy +/- .0025 in