This models a cutout for a MAF Corp. Heat Set Serial Number Tag. The tags give you an easy way to serialize a 3D printed firearm or suppressor to comply with US Federal (NFA) and/or state/local serialization requirements. With this cutout model, you can use the slicer to create a recess in an existing model that the tag will fit into. You can permanently affix the tag using epoxy or melting the protruding pins to hold it in place.