Fits directly on the Cross Slide direct of your Myford Lathe. However Can fit to Larger Machines by using Packing to Adjust Center Height Bearing Base Smooth Rotation- Can turn up-to a 42 mm diameter Metal or Wood Ball. Can be Adjusted for Various Sizes of Balls using the reference scale graduated in metric and imperial sizes. Supplied with 2 Pcs x 3 Sided Indexable TNMG16 Tips along with a spare box of 10 pcs cutting inserts. Designed to make convex ball and cut concave curvature (* pls refer to the image in the ad) The much demanded graduations in imperial and metric measurements are now being provided as a reference scale for turning a approx ball diameter calculations. Its is important to note that the scale provided is for a close idea of the diameter of the desired ball size. It should not be referred for an exact measurement by the users. The insert tip should be adjusted to the given reading for achieving the desired size of the ball. Pls note the scale is a radius reading, which means that for any set parameter on this scale, you will get double of it as the ball diameter. Example- If you set the scale at a measurement of 15 mm, you will get a ball size of diameter 30 mm. The attachment has both Imperial as well as Metric graduations on either size of the attachment.