1.The dome pushes the water line away from the lens,the field of
view is increased, above and below the water line,it gives you very
cool pictures.
2.The water magnifies things.This distorts the look of the photos,
making the above water objects look normal while the underwater
objects look larger.
3.With the dome port,it normalizes the field of the views,it
matches above and below the water line,which gives you
a real world.
4.For Gopro 4 black version with added LCD screen, or others with
LCD screen,but not Gopro 4 session.
5.Dome with Shading cover,better Better light photography
Kindly Note: Please pressing harder between the dome port and the camera
housing case,and screw down the screws and test before diving