Replacement lens kit for the GoPro Hero 8 Black (will not work on other models). 

Yes, really!  Get them while they are still available.

Made from ultra-strong Corning Gorilla glass, These are a direct replacement for the Hero 8 glass lens on the front of the GoPro.  If you have broken or scratched your Hero 8 lens, this is for you.  Includes a tool to help remove the old lens and pre-applied ultra strong adhesive to keep it on.

It's a super simple swap that just takes a few minutes, and it comes with everything you need, except a heat gun or hair dryer:

• Replacement lens
• Pre-applied adhesive
• Tool to remove the old lens

You supply the heat gun.  A hair dryer will also work (you just need to use it very close)

Note that replacing the lens may void your warranty, and could reduce water resistance of the camera especially if not installed correctly.

Full instructions here.