The principle of hooking is to set the arrow hook on the inner folding sheet. When the arrow hook is fastened by the spring sheet of the watch case cover, the spring release keys on both sides of the case cover must be pressed to release the hook. The utility model has the advantages of stable and safe buckle, smooth and beautiful outer edge interface of watch strap, light pressure on wrist when buckle, convenient and fast use. The disadvantage is that there may be problems of hook body wear and spring fatigue? The service life is closely related to the material used. Most of them don't have micro adjustment of watch band length. This kind of folding body can be in different forms, including laminated sheet, combined concave and convex board, and the combination of concave and convex board is better.
