Backdoor for Garmin VIRB Ultra 30/HERO3 /4/5/6/7

Backdoor for Garmin VIRB Ultra 30/HERO3 /4/5/6. This backdoor makes it possible to install the VIRB Ultra 30/ HERO3 /4/5/6 on a GrellFAB-mount.
Compatible with GrellFAB-mounts;