GoPro Hero 3 Black Edition User Manual page 61

The HERO3 housing comes with two types of backdoors—Skeleton and Standard.
skeleton Backdoor
The Skeleton Backdoor (non-waterproof)
provides better sound quality by allowing
more sound to reach the camera's
microphone. It also reduces wind noise
at speeds up to 100mph when mounted
on helmets, motorcycles, bikes and other
fast-moving vehicles. Use this backdoor
only when sand, excessive dirt/dust
and water damage is not a risk. This
backdoor is also recommended for use
inside vehicles.
Apply RAIN-X or a similar anti-beading solution to the housing lens
Pro to prevent waterspots from forming when using your camera in rain
tiP: or water. When RAIN-X is not available, periodically licking your
lens is a good backup solution. Trust us, this works.
camera assemblY
standard Backdoor
The Standard Backdoor makes the
housing waterproof to 197'/60m.
Use this door when you need to
protect the camera from water and
other environmental hazards.
61