A gui is a type of bowl-shaped ancient Chinese ritual bronze vessel used to hold offerings of food, probably mainly grain, for ancestral tombs.
The shape changed somewhat over the centuries but constant characteristics are a circular form (seen from above), with a rounded, wide, profile or shape from the side, standing on a narrower rim or foot.
[3] The British Museum bowl inscription on the inside of the bowl tells that King Wu's brother, Kang Hou, who was the Duke of Kang and Mei Situ were given territory in Wei.
The inscription relates a rebellion by remnants of the Shang, and its defeat by the Zhou, which helps us to date it.
Because historians know exactly when this unsuccessful rebellion against the Zhou dynasty took place then the bowl can be dated very accurately.