The Olfi Anti-Fog / Moisture Inserts have been developed to use in cold or humid climates to avoid excess moisture building up on your lens and ruining your footage with a fogged-up lens as well as helping prevent water damage to your camera.Helps maintain crystal clear footage from your cameraReduces the chance of water damage associated with excessive condensationReusable use up to 4 times before baking in an ovenAlso compatible with GoPro camerasMade from high-quality silica gel on cellulose fibre, these inserts absorb moisture and keep it away from your camera. These great little problem solvers are ideally suited for use with the Olfi Waterproof Case. Place these little beauties down the side of the case by the USB/HDMI ports on the camera, not at the back of the case. Don t forget, you could also ruin your camera if moisture from excessive condensation droplets find their way inside the ports. There are 12 inserts included in each pack and each insert can be used up to 4 times