(1) from the back cover to remove the direction.(2) from the table glass out. The vast majority of watches are removed from the table cover the direction of movement, the latter case is often because the dial diameter is too large and the table back cover diameter is relatively small reason. The structure of the case is also divided into two and triple, the so-called second only is the case and the table back cover (table glass is not), the so-called triple is in addition to the case and the back cover, there is a case before The front end of the case is usually pressed or screwed to the case shell, so the main purpose of this design is to remove the movement from the glass in the table, of course, Some for the appearance of decorative needs. Triple the case structure is more complex, disassembly is also troublesome, the main problem is waterproof, because it is more than a second case of a waterproof seal, so to ensure that the watch's waterproof performance is not easy to do.