What is the array of four symbols around the Five Thunder Rings?

There are four symbols in the southeast, northwest and around the Five Thunder Commandments, which are array methods for exorcising evil spirits. The Five Thunder Rings is a musical instrument used by the Taoist School of Divine Night. Generally, most of the important props used for practicing at the altar are keepsakes, and some strange words are engraved on them, called Wu Lei Wen, or Wu Lei Shu and Wu Lei Fu. This kind of writing is usually a combination of Chinese characters and Chinese characters, Chinese characters and graphics, with their respective pronunciations, which sounds unfathomable. If you are a person who knows calligraphy, you can see that Wu and Shou Jin have many similarities, especially the strokes, which are exactly the same. This is because Song Huizong, the Emperor of the Northern Song Dynasty, advocated Taoism at the banquet, which was highly respected, so he left traces in Wu.