HHIP 4901-0003 4 Piece Combination Square Set (12" Blade) 0-12" Blade ~ Blade is made of hardened stainless steel Double indexed protractor is graduated 180 in both directions Microfine graduation. ~ Graduation: 4R-8ths, 16ths, 32nds, 64ths Set includes: square head, center head, protractor and blade Accuracy 15'