I bought a used pretty cheap Yi Gimbal and needed an adapter to fit my GoPro Session.
The GoPro fits snug in the case and the case itself is secured with 2 M2x16 screws.
It has a round cutout to be able to control the GoPro without having to remove it.
I could have modeled a little hole in it for the SD Card door, but I am going to use this on my bike so I wanted it to be as sturdy as possible.
Maybe I'll make a second version.
It seems like the GoPro is not balanced enough so it always hangs a little to the right, so I just glued 7 M6 nuts to the left side of the case (left when lokking where the camera films) to balance it, seems to work.