The UltraTest Combination Measuring Set brings you the power of a square, ruler, protractor and centering gage in one convenient design. The hardened and heat-treated heads attach to the 12 in. satin chrome blade for taking a variety of measurements with ease. The Square Head provides 45 and 90 degree angles and also features a level and hardened scriber. The reversible Protractor Head measures odd angles with precision accuracy, and the Centering Head allows you to find the middle of round stock. The set also includes a locating screw on each head for faster attachment to the blade. Four piece measuring set for limitless applications. Hardened, heat treated heads with ground and polished measuring surfaces. 12 in. high carbon steel rule with etched graduations and satin chrome finish. Square Head for 45 and 90 degree angles. Reversible Protractor Head with double shoulder for odd angles. Center Head for use with round stock. Spirit level and hardened scriber included with Square Head. Graduations in 1/8, 1/16, 1/32 and 1/64 in. Locating screws allow for easier attachment of heads to ruler. Meets government specification GGG-S-656C.