Sherline's steel gage offers a simple way to assure the tip of your cutting tool is set to the centerline height of the lathe. The lower lip is for tools in the standard toolpost, while the upper lip is used with the riser toolpost. Just set the gage on lathe table and position it in front of the tool tip to check to check height. It is much quicker and easier than checking height against a center in the headstock or tailstock.