This kit makes a versatile tool that can be used in two modes. In the ball turning mode, seen in the photo, the toolpost is being set up to locate for the final cut in turning a sphere. The ball turning mode requires no complicated worm and wheel or micrometer adjustment to turn accurate radii. Spheres up to slightly more than 1 1/2" diameter can be turned on South Bend 9 inch lathes. Larger lathes may permit larger diameters. Concave surfaces can also be turned. For the boring mode, a sturdy casting is supplied for a toolholder that mounts on the base casting. The toolholder accepts boring bars up to 3/4" diameter and is exceptionally rigid. It may also be mounted on the topslide compound. The kit includes five iron castings, drawings, and illustrated machining and operating instructions.