Shuanglongzhu refers to the number 8. Split 8 from top to bottom, that is, two S in opposite directions, just two dragons, and the circle formed is a bead.
Since the Western Han Dynasty, dragon playing with beads has become an auspicious and festive decorative pattern, which is mostly used for architectural color painting and noble and luxurious vessel decoration. The shape of Ssangyong depends on the area of decoration. If it is a dragon, the two dragons are symmetrically located on the left and right sides, showing the posture of walking dragons.