【Insert these Anti-Fog Inserts】into any GoPro waterproof housing or dive housing to prevent fogging in cold and humid environments. Inserts will last up to four uses.【Reusable】Anti-Fog inserts will be reusable up to four times【To dry out and reuse】heat inserts on a pan in the oven at 300°F for five minutes. Store in an airtight bag.