This small solid object was used on the corner of a mat to keep the mat from curling. Mats were placed on the ground to be used as seats, as there were no chairs during the Han Dynasty, people just sat on the ground. The mats have a tendency to move easily when people sit down or stand up. So four mat-weights named Jia, Yi, Bing, Ding, respectively, when placed on the top of the corners of a mat, will prevent the mat from moving. [Photo/dili360.com]