Starrett 435-12-4R Combination Square with square head, center head, and reversible protractor head and blade A choice of stable cast iron protractor - reversible is nicely finished with a black durable finish Graduation: No. 4R - 1/8", 1/16", quick reading 1/32", 1/64" With reversible lock bolts, scriber, spirit level in square, center heads and protractor head Direct reading double 180 degree protractor scale Cast iron heads with black wrinkle finish Cast Iron Heads with black wrinkle finish 12" hardened steel, machine divided blade Reversible lock bolt, scriber, and spirit level in both square head and protractor head Graduation is 8ths, 16ths, Quick Reading 32nds, 64ths Direct reading double 180 degree protractor scale