The file 'DM Screen Card Holder/Initiative Tracker – 3mm Wide 3D Printer Model' is (stl) file type, size is 11.5KB.
The original clip posted by HyenaLobster had some issues. I used one of the remixes posted in the comments of that Thing. I modified one end to fit my 3mm thick DM screen. The other was a bit loose on my cards even with a dragonskin case, so I shrunk it down to fit snugly but not tightly so it shouldn't mar the card. I have printed and tested this with success.
FixedClip2.stl | 40.2KB |