The phot r anti fog inserts is the perfect accessory for your gopro or other sports dv cameras it fits perfectly inside the waterproof housing to prevent your videos or images being ruined by the misting or fogging that occurs when filming in mixed temperature and humid environments it prevent condensation that can build up between the gopro camera and the camera housing hero and hero2 owners should place one insert on either side of the camera hero 3 and 3 owners should place one insert o