Some glass technicians drill every break to allow better resin filling on their repairs. This diamond burr has fantastic durability when drilling glass breaks. When your finished with the delivery of the resin, you can use this burr to roughen the pit surface for better pit filler adhesion. These bits are sold individually and being made with diamond, they have a longer life than our standard burrs. Trust AEGIS Tools to bring you the best in glass repair tools. Buy a diamond burr today for your glass business!