Review on General Tools 823 Protractor Increments by Dan West

Easy to use. Has no switch; turns off automatically. Well how accurate it is. I measured the angle and cut a piece of plywood. Because the size was so large, I had trouble using a real line marker tool accurately, so I did some math and used the tangent function to calculate the second side of the triangle. I cut it out using this line given to me by the angle measured by the tool. At steep angles of 0.53.8°, slight deviations from the vertical result in huge gaps or it doesn't fit at all. My special haircut fit perfectly.