The slave clock is composed of various specifications, with dimensions of 3-inch, 5-inch, 8-inch and 10 inch. It can also be customized according to customer requirements. In various sizes, it can be divided into single side and double side. On the basis of the above, whether it is output by hour, minute and second, or year, month, day, hour, minute and second; or year, month, day, week, hour, minute and second; the address code of the slave clock can be set and changed by turning the switch on the slave clock. At the same time, the digital slave clock has the memory function, built-in real-time clock chip, which can automatically resume normal operation after the call.