This is a clip to mount a GoPro camera to the bill of a hat, I've been looking for something like this for a long time and couldn't find anything that did this. It's a simple friction mount clip with a GoPro Slide mount. Very simple, but it does the job. It keeps you from having to drill a hole in your favorite hat!
I printed mine with 70% infill, I would suggest at least that to keep it solid enough, since it has to hold while you're moving.
I hope it works as well for you as it does for me.