The jade rings were always placed close to the head of the coffin, and carved on the outside--some had four prominent protuberances, while others did not.
玉玦的發現多在頭部的左右，其造形大抵內成圓形，外部則變化不一，有的成方形，有的成圓形，有的在圓形的外面有四個突起。