This is for the Garmin Instinct watch. The instinct is a 45mm model. I've included pics of other models for comparison. Hopefully that helps.
For any of the Fenix models: Let me know if yours fit. They have the charging port in the same location on the watch, but those are 51mm models, so I don't know if those fit. Leave a comment and I will update the model! =]
I took the previous design (by @Patrick) which was for a Garmin vivoactive 4, and then mirrored it in tinkercad to make the charging hole on the opposite side so that it fits the Instinct. The charging hole location on the Vivoactive is at 3 o'clock, the charging hole location on the Instinct is in the 9 o'clock position.
I really liked @Patrick 's simple, solid design, and wanted it to fit my Instinct watch. Other watch holders seem to be easy to tip over, this one is really solid.
Edit: Fixed and re-uploaded on 1/1/25 to fix 2 degree tilt of object on import (face not flat on surface).
The author remixed this model.
I mirrored the previous design in tinkercad to make the charging hole on the opposite side so that it fits the Instinct.