Made with a patented diamond bonding process for extra long life. Creates a groove to fit 16 and 18 gauge wire. Assists in securely wire wrapping 3-D glass sculptures and glass jewelry. Eliminates the need to glue jewelry findings. 220 grit. Fits Glastar G3, G4, G7, G12, G14 and all Inland Grinders. Close-up of this item below. Step-by-Step: Wire Wrapping Using a Jewelry Bit See images below 1. Grind a groove around edges of glass cabochon with a jewelry bit. 2. Wrap wire around cabochon firmly from bottom, ending at top. Grip wire with pliers and twist to secure. 3. Bring wires up and wrap around a dowel 1/4" away from cabochon. 4. Using wire nippers, trim ends around base to secure and tuck in ends. Images from "Innovative Adornments" book #6294. Artist: Jayne Persico.