Charleston slave badge from 1807 for Servant No. 20

This is an octagonal metal slave badge. On the recto is text that reads ”CHARLESTON [stamped]” across the top. Under that is “No. [stamped] 20 [engraved] / SERVANT [stamped] / 1807 [stamped].” On the verso is a stamped cartouche at the bottom center with the maker's name “C PRINCE.” There is a hole punched at the center top.