Combination Set Number of Pieces 4 Blade Finish Brushed Blade Material Steel Head Length 2 1/4 in Head Width 7/16 in Blade Length 12 in Blade Thickness 0.06 in Blade Width 5/8 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 Cast Iron Head Vial Included No Accuracy +/- .0025 in Features Reversible Lock Bolt