What is the semicircle thrown by Minnan in divination?

In Minnan dialect, ball-throwing is also called "Babei", and in Central China and Southwest China, it is called "Guagua". It has two front parts shaped like horns together instead of a semicircle, and there are various types.

According to the traditional custom, the content of the ceremony is to throw two half-moon cups about the size of a palm, one flat and one convex, to explore the meaning of ghosts and gods.