1° Vernier markings for dressing angles. Magnification, through hole in the spindle, makes it possible for the operator to see how to dress the form on the grinding wheel. Fixed Focus Lens (3X). Wheel form grinding done easily and accurately. Furnished with 90° phonopoint diamond. Compact design. Case. Swing Arm 180°, Max. Size Grinding Wheel 8". Max. Outside Radius (on wheel) 5/8" approx. Max. Inside Radius (on wheel) 1" approx. Spindle 1" O.D.