Yubikey Keysmart Adapter

Print it the holder and the spacer for the opposite side. I have the original Keysmart, to user that with a more Keys you have to buy the “Expansion Pack” fort the Keysmart. 

I've tested a different versions. I printed them with ABS on a Prusa MK4. No Supports needed but an enclosure is required if you are using ABS. 

PETG should work also very well. As long as the material is not to brittle. The Clip holds the Yubikey in Place. NFC Works fine. You can turn it and hold it to your Phone without removing it from the holder. If you want to use it over US you can remove it from the holder.