With precision clear accurate readings, our angle swing arm protractor is easy to read. The round head protractor has a 0-180 degrees semi-circle scale, can forward and reverse directions to measure any angles. The protractor arm can be adjusted to any angle you want, which is easy to use. And metal material is sturdy and durable, so can last for a long time. Features -Color:Black -Material:Aluminium alloy -Size:20.30X10.00X1.20cm/7.98X3.93X0.47in - The protractor is made of metal, not easy to wear, smooth edges, fine grinding, accurate measurement. - The ruler and protractor makes it can measure length by fixed ruler and measure length by moving ruler. - Semicircular protractor at the upper can measure from 0-180 degrees left to right and right to left. - Swing arm protractor read numbers and read angle marker, then adjust the nut, you can fix the angle. - Suitable for engineering, angle measurement, drawing, architectural design, carpentry, length measurement. Package list: 1 x Rotating Angle Ruler