The Starrett C435-12-4R 12-inch Combination Set with Square, Center and Reversible Protractor Head and Blade a complete substitute for a whole set of common solid try squares, a 45 degree miter, a depth gage, a height gage, a marking or scribing gage, a level, a plumb and, by withdrawing the blade, it can also be used as a precision rule. The combination square with center head is a basic combination set. The center head is a convenient and accurate way to find the center of round work. Features: Readings in 8ths, 16ths, Quick Reading 32nds and 64ths Spirit level in both square head and protractor head Direct reading double 180 degree protractor scale Cast iron heads with black wrinkle finish Hardened steel, machine-divided blade Reversible lock bolts Scriber What's In The Box: Starrett C435-12-4R 12-inch Combination Set with Square, Center and Reversible Protractor Head and Blade