4 Pc Combination Square Set with Cast Head Set includes... Square Head Center Head Protractor Head Machinist's Blade Features include... 12" Blade Length Blades are fully hardened and tempered. Durable, easy to read satin chrome finish. High contrast, micro-fine blade graduations. Square/Miter head features a level vial and hardened scribe tool. Protractor scale graduated from 0 - 180° in both directions. Furnished in fitted case. Graduations... E/M: 1mm, 64ths, 32nds, 1/2mm