Commonly, bēi jiāo (a traditional divination tool in Chinese folk culture) is made from materials such as copper, bamboo, wood, and shells, and is usually used in a pair of two pieces. There are mainly two types of shapes:One type, when the two pieces are closed, resembles the horns of cattle or sheep. Each piece has a flat side (considered "yang" in traditional Chinese Yin-Yang theory) and a convex semicircular side (considered "yin").The other type is called "yuèguāng bēi" (moonlight cup) or "yuèguāng guà" (moonlight divination). When the two pieces are opened, they form an oval shape; when closed, they look like a crescent moon.The culture of bēi jiāo is particularly prevalent in regions such as Fujian Province and Chaoshan (in Guangdong Province). For example, in the "Yíng Lǎoyé" ritual (a traditional folk activity in Chaoshan where locals honor and parade with statues of deities) in Chaoshan, bēi jiāo is frequently used. People seek the "deity’s opinion" through a divination ritual called "bá bēi" (casting the bēi jiāo), making it an important part of the local folk culture.The divination results are interpreted based on the orientation of the two pieces after casting:When the two pieces show one "yang" and one "yin" (one flat side up and one convex side up), it means the deity approves the request—the matter is feasible, and the wish is likely to come true. This signifies that things will proceed smoothly, representing an auspicious outcome.When both pieces show "yang" (both flat sides up), it indicates unclear communication with the deity, no clear judgment can be made, or the opportunity has not yet arrived. In this case, people need to consult again. It implies uncertainty about the matter, requiring further observation or reflection.When both pieces show "yin" (both convex sides up), it means the deity disapproves the request. This implies that the current idea or plan may be inappropriate and needs to be reconsidered or adjusted.