Kangxi Bao Tong copper coins are serrated outside, much like circular saw blades on woodworking machines.

This kind of coin is caused by human factors in the later period, and its function is different. One is that the accessories used by the ancients for decoration are similar to the current brooch, but the divination is at the waist. There is also a saying that ancient divination is a tool to summon gods and suppress ghosts. There is also a less credible saying that children's toys. None of the three statements is elegant, but there are real things in the world. However, due to the later artificial carving, the aesthetic level is not good, not favored by collectors, and the market value is not high. It only costs about ten yuan.