Feature: 1. Made of rubber material, good flexibility, wear resistant, durable. 2. The watch's rubber O-ring can keep the watch waterproof. 3. Suitable for watchmakers and watch repairers. 4. 10 sizes to meet your needs, the included plastic box has 10 grids to keep all parts organized and easy to carry. 5. Having excellent workmanship and suitable for various watches. Specification: Condition: 100% new Item Type: Watch Crown O-Ring Material: Rubber Model: NO.4052 Package List: 1 x Watch Crown O-Ring Box (10 Grids)