What is the meaning of Yao Su compass?

Yao Su: It means constellation. It comes from India, similar to Twenty-eight Nights in China. Refers to the twenty-eight constellations of the White Road operated by Taiyin. In the Tang Dynasty, tantric translated Yao Sujing, a book introducing Indian astrology. Its main content is to interpret good and bad luck and explain the method according to the running orientation of seven nights, twenty-seven nights and the zodiac.

Compass: an instrument for determining the direction. It consists of a disk with azimuth scale and a compass installed in the middle. It is also used by geomantic omen or astrologers to predict divination.

Explanation: Yao Su compass is a special compass for divination based on the principles of Indian astrology.