The cong are prismatic jade objects with a circular hole, frequently found in the tombs of the Liangzhu culture, placed all around the body along with small-sized bi discs. It is believed that these objects, like bi discs, were associated with the ruling class as a symbol of political power and, possibly, spiritual power as well. The corners were often decorated with taotie (饕餮) masks or simply with horizontal cuts along the object, revealing advanced knowledge of the techniques of the cutting, perforating and abrading the surface of jade.