The DampFree Slimline Refills are designed for use with the DampFree Slimline Unit or other suitable 350mL spill-proof, moisture absorber containers. The crystal formula works by gradually pulling moisture from the air and protecting against dampness, rust and musty odours that could damage your things. To use, dispose of your old Slimline Crystal Sachet and any residual liquid from your Slimline Unit and replace with a new Refill Pouch, ensuring the paper side of the refill is facing upwards. Replace the lid and sit in place. Your hands-off approach to a damp free environment is now ready. Do not use near metal and leather goods.