If you use closed housing is mandatory, you definitely had to deal with fog forming on the lens after some time of use. This is almost inevitable, because your GoPro naturally heated during operation and the temperature difference between the interior of the sealed housing and the outside causes the fogging of the lens. You can try all the tricks offered on forums ... you will eventually try and adopt these inserts and you bougerez more. It is the only truly effective way to fight against this problem, I've experienced!
