This item is made of high quality stainless steel, anti-rust, durable and sturdy to use. Its measuring range is 0-180 degree and finished with a bevel edged extension blade, roller knob and fine adjustment. With a 5' (minute)/0.08 degree accuracy and laser engraving scales, it's great for measuring inner and outer angles of the parts. Features: Made of high quality stainless steel, anti-rust, durable and sturdy to use. A case provided to you, convenient for you to use. 0-180 degree measuring range, and its accuracy is 5' / 0.08 degree. Each scale line is engraved by Laser, so it is laser engraving scale. Finished with a bevel edged extension blade, roller knob and fine adjustment. Great for measuring inner and outer angles of the parts. Instruction: Calibration measurement should be zero, universal angle ruler zero, when Square are fitted with a ruler, and the bottom edge and the base Square foot in contact with the ruler without a gap, then the main scale "0" line aligned. After adjusting the zero position by changing the mutual position of the base scale, angle square, straightedge can test any angle within the range of 0-180 . Specification: Condition: 100% New Color: Green (Shown as picture) Material: Stainless Steel Measuring Range: 0-180 degree Accuracy: 5' / 0.08 degree Package Weight: 1.358kg Package Included: 1 x Universal Bevel Set 1 x Case (Full Components Shown in Picture)