Clock devices are considered components that aren't constantly included "components" in developing a watch from scratch. The accessories to a clock are non-functioning, non-essential, and due to the fact that the clockmaker can securely dispense with them, they have to be bought independently if wanted. They may indeed be desirable as novelties or extensions to timekeeping, but there are also circumstances, such as for reconstructions, in which just one or two operating parts need to be bought as substitutes.