Hemisphere styli are suitable for measuring undercuts as well as for those applications that require a large diameter of the stylus tip with low weight. To enhance this effect, n is a distinction made between hemispherical and hollow hemispherical styli. Hollow hemispheres are produced using a complex manufacturing process in order to achieve maximum weight savings. For VAST XXT probes, hemisphere styli are not suitable for weight reasons. Only hollow hemisphere styli are used here.