Feature: 1. 3135 main spring specially designed for repairing mechanical movements. 2. Ensuring normal operation and stable performance of the mechanical movement. 3. Professional accessories for mechanical watch repairing will give you a satisfactory experience. 4. Suitable for watchmakers and watchmakers, practical and wonderful tool. 5. Wonderful replacement for the old or broken one made of high quality alloy material. Specification: Condition: 100% brand new Item Type: 3135 Main Spring Material: Alloy Use: Used to replace broken or old movements in watches Model: 3135 Package list: 1 x main spring