Charleston slave badge from 1811 for Servant No. 180

This is a square metal slave badge with quarter-circles cut out of the four corners. On the recto is text that reads ”CHARLESTON [stamped]” across the top. Under that is “1811 [stamped] / SERVANT [stamped] / No. [stamped] 180 [engraved] .” There is no legible cartouche on the verso. There is a hole punched at the center top.