Review on Japanese Mitre Square by Shinwa 62103 by Brandon Page

On the back of the packaging it says that an accuracy of up to 0.01 mm per 100 mm is guaranteed. If my math works, it's accurate to within 0.01 degrees (arcsin(sin(pi/4)-0.0001). For reference, Incra's guaranteed tilt angle of 45 degrees is accurate to 0.001 inches by 5 inches, or 0.02 degrees (arcsin(sin(pi/4)-(.001/5))) and Starrett's combined square is accurate to 0.004" x 12" or 0.003 degrees. I'm very happy with that. - James