Two Chinese characters Wu Zhu (=5 Zhu), shallow outer rim / Blank, no rims. 26mm, 2.53 grams. Schjöth #304; Hartill 10.27.

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. 

The Southern and Northern Dynasties (420589 AD) was a period in the history of China, following the Jin Dynasty (265420) and followed by the Sui Dynasty. It was an age of civil war and political disunity. However it was also a time of flourishing in the arts and culture, advancement in technology, and the spread of foreign Mahayana Buddhism and native Daoism. Distinctive Chinese Buddhism was also matured during this time and shaped by the northern and southern dynasties alike. The establishment of the Sui Dynasty and the invasion of the south reunified the whole of China by the end of the 6th century AD.