This holds 6 of the metal business cards from Elegoo. there are magnets in the bottom that help keep it in place, as well as a spot for a thin magnet on top to keep the cards in place. There is a hole in the center so you can use that to set the origin of the laser engraver.  I have a DXF file i can so that you can bring it into Lightburn so you can use it to index the tings you are engraving on the cards. I have an Elegoo Phecda engraver but this may work with other brands