Size 6-1/4" X 9-7/8" 1/16 to 2-1/2 axes. All are 35° - 16' projection. Dimensions are for isometric axes. Half of the 2-1/2 ellipse is surrounded with pinholes spaced at every 15 isometric degrees. Lifetime precision centering pinholes are provided for major, minor and isometric axes.
