Two Chinese characters Wu Zhu (=5 Zhu), shallow outer rim / Blank, no rims. 26mm, 1.31 grams. Schjöth #304; Hartill 10.27.

The host coin is a private issue Eastern Han Wu Zhu.

These coins are the late Wu Zhu coins are called "Yan Huan Wu Zhu" ("Thread Ring Wu Zhu") because their center was removed (either to yield a Zao Bian (Chiselled Rim) Wu Zhu's. These coins are relatively scarce.