Anti-Fog inserts helps prevent a camera's housing from fogging, even in cold temperatures/humid environments.
Owner Reviews, Ratings, Comments and Criticism
The first time I took my GoPro up in my open cockpit ultralight plane, I was saddened to find out, at the end of the flight, my GoPro case had fogged up pretty badly. Imagine my surprise when I discovered that GoPro makes these strips to combat that exact problem. I bought some and they do indeed work. I've had a couple flights now and the case remains dry and the resultant videos crystal clear [...].
But they're expensive strips of paper. They're not really paper, but whatever they are, I'm sure if you Google for a DIY solution, you'll find some. I think people have been using cork with decent results.
However, if you're after a quick, need-it-now solution and have $14 to spend, these works well and are indeed reusable. The package comes with a paper hydrometer (or hygrometer?) that detects moisture in the zip lock baggie they come with. Let's you know if they're still good, I guess.
