Excerpt: I brought two different inserts on a week diving with these, and I swap in a fresh battery before each dive. That's a lot of opening and closing in humid conditions.
These inserts seemed to me to be really bad at absorbing more than a minuscule amount of moisture.
Excerpt: Before my dive, I stuffed 2 of theses on the insides of my Gopro housing. No issues with fog. I must state that the water I was diving in was 83 degrees and air temps were about 87. I would definitely use again.
Excerpt: A must have if you are in the cold or wet area. I used them on a recent ski trip and regularly when sailing and using the GoPro.
Keeps the fog from forming and guarantees the best possible pictures.
Excerpt: I have no idea if this product is really necessary. Maybe if you shoot a lot under water. I don't believe these are necessary unless you heat and cool the camera a lot. I live in the humid south and have yet to fog up my camera. These probably will sit in a drawer for years.
Excerpt: Absolutely necessary for water work with my GoPro 3+ Black (when it's in the standard waterproof housing). I usually use three of them at a time if I can, for activities like scuba diving and whitewater rafting.