Original Design: https://www.thingiverse.com/thing:4853032
I quite liked the design but I wanted to use threaded inserts to mount the AirTags securely to a bag.
Parts needed:
4x M3x8 screw
4x M3S (short, 4mm) threaded insert
assembly:
put the threaded inserts in from the bottom (the flat side). Put everything together with the strap sandwiched in between and screw it together.
updates
2022-05-03: added extrawide version to accommodate 40mm straps
The author remixed this model.