Now You Can Confidently Work On Rolexes And Not Worry About Damaging The Oyster Case! Six Tempered Metal Rings (18 1/2mm, 20 1/5mm, 22 1/2mm, 26 1/2mm, 28 1/3mm, And 29 1/2mm) Let You Work On All Sizes. The Interlocking Design Gives A Secure Fit. Wooden Case Included.