Size 6-1/4" X 9-7/8" Major axes 1 to 45mm. 44 ellipses 35° - 16' projection.
Dimensions are for isometric axes. Inch equivalents are given in small type. Half of the 45mm ellipse is surrounded with pinholes spaced at every 15 isometric degrees. Lifetime precision centering pinholes are provided for major, minor and isometric axes.