With the Spherical Miracle™ brand diamond wheel you can grind a spherical depression in your workpiece. The radius design produces more cutting power than conventional flat wheels ... delivering a double bite. This wheel promotes high visibility of the point of contact with the stone, allowing you precise control of the cutting outline. The Spherical Miracle™ brand diamond wheel will also remove punting marks. The 1" arbor hole is bushed to 3/4", 5/8" and 1/2".