Charleston slave badge from 1803 for Porter No. 480

This is a round metal slave badge. On the recto is text that reads ”CHARLESTON [stamped]” across the top. Under that is “No. 480 [stamped] / PORTER [stamped] / 1803 [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.