The latest GoPro Hero 6 has rubber buttons which are pressed by small metal pins if a waterproof housing is attached to the camera.
For my GoPro Hero 6 the housing from the following link is used:
A big problem with the new GoPro, its rubber buttons and the metal pins from the housings is that the metal pins could damage the GoPro's rubber buttons over time.
At the beginning the original GoPro Dive Housing ( https://www.camforpro.com/gopro-super-suit-housing-fuer-hero5-6-black/ ) had bigger pins which pressed on the GoPro rubber buttons. However, for some reason this was changed and the new housing only has small metal pins as you can see in the attached photos.
The "GoPro Button Saver" presented here allows attaching small plastic parts onto the metal pins to enlarge the size of the pin which presses on the GoPro rubber buttons to save the buttons.
My Button Savers were printed with PETG and I glued them with two-component glue to the metal pins to avoid losing them when no camera is attached.
As I don't have my own 3D printer, the parts were printed by https://www.3dhubs.com/service/83913 (thanks Andreas :-)
The OpenScad model is based in the following library: