I found a great color keychain model, but since I don't have an AMS/MMU system, I redesigned it for printing on a single-color printer. As a bonus, the model has been redesigned so that if you print two and glue them together, you'll get a double-sided keychain.
Good luck with your printing!
Der Autor hat dieses Modell remixed.
The height of the parts has been changed for printing on a single-color printer, the bottom part has been redesigned to allow for smooth gluing of the parts.