AanrAanraku Twofers JEWELRY Grinder Bits 220 Grit (2 bits per package) - Use jewelry bits to grind a groove into the edges of jewelry for finishing and wire wrapping. A huge time saver and your jewelry pieces will be more durable.- Fits most Glastar grinders- Grinds a groove for 20 or 18 gauge wire.- 1" diameter Grinding Bits with 2 Allen keys