Back cover. Open the back cover, press the button to remove the handle shaft, then close the back cover, turn the watch over and put it on the table, and pick up the case to operate. Shanghai brand watch is a watch brand in Chinese mainland, which was launched on 1955. Its watch is the first thin horse watch in the history of China. Because both China people and Zhou Enlai, the founding prime minister of China, have worn Shanghai brand watches, they are called "the national watch" in China or "the first watch in China".