Set Comes With 15 Different Diameter Borers. Nickel-Plated Brass Pieces Are Stackable, Includes A Cleaning Rod And Individual Handles On Each Borer, Are: 4Mm, 5Mm, 6.3Mm, 8Mm, 9.5Mm, 11Mm, 12.6Mm, 14.25Mm, 15.8Mm, 17.4Mm, 18.9Mm, 20.6Mm, 22Mm, 24Mm, And 25.4Mm.