Review on Accurate and Versatile: Exploring the Johnson Level Tool 406EM Combination by Cornelius Mosley

This square was accurate and square in length, but difficult to read (glossy) and the ruler jigged in the head, even when it was locked. were accurate in inches and millimeters compared to the reference rules. Not that good compared to the two 6 inch squares I have. I bought it for the mm scale on the square.