Big Horn 19070 Plastic Protractor. Measure or transfer outside angles, inside angles, and sloped angles with Big Horn's plastic protractor. It can also be used to make miter angle layouts. Made from yellow, high impact plastic with easy to read scale and brass tightening screw to lock in any position. Long arm is 5-3/4-Inch and the short arm is 3-1/4-Inch. Comes with instructions. Measure or transfer outside angles, inside angles, and sloped angles. Can be used to make miter angle layouts. Easy to read scale, Tightening screw locks in any position.