Zeroes the spindle much easier than other edge finders. The 3/4 inch shank is also very handy (not metric). I used it to attach my vise to the spindle and then checked the toolpath with the specified (new) vise. I can now set this value (or 0) and run through a vise to check one end and pull across. The same goes for checking the other axis of the vise relative to the spindle. Easier/faster setup without having to calculate edge finder values for spindle center Interpretation errors when you need to apply an offset. Highly recommended for anyone who has a milling machine and wants to simplify or speed up the setup process (or both).