DDT***M14 FINGER vacuum brazed diamond finger router bit. Wet & dry application for porcelain & ceramic tiles, plastic & PVC , granite, fibreboard, masonry & building material. Designed to create any shape, enlarge or widen or increase diameter of existing holes and eliminates the need for a diamond core drill bit for every diameter. Speed and convenience with M14 thread for direct connection to angle grinders. Operate at full rpm speed, do not force, apply medium pressure with slight circular motion to allow for debris removal and cooling. Excessive pressure can lead to diamond crystal pull out and reduced lifetime.