Review on GoPro Anti-Fog Inserts: Ensure Clear Vision with Official GoPro Accessory by Chris Shepherd

I use them underwater at <40 degrees Fahrenheit water and air temperature and they work great. Before using the inserts, I had serious fogging issues in the sealed GoPro case when the temperature started to drop to 60 degrees. These inserts do the trick and I use 3 at a time as recommended. I've baked and reused them over and over again and they continue through a couple of holes in the body for changing batteries/memory cards in the camera. The little humidity sensor machine that comes with them is useless. If I ran into his display areas, my bets would never be "active" and would never work. This is unnecessary and inaccurate. CAUTION: Make sure the inserts DO NOT touch or interfere with the seal around the door; GENERAL. If it does, adjust them until that happens, otherwise the case will leak (albeit slowly) and you'll end up with fog (or water, if that's bad).