(1) Metal Safe Vapor Cube Corrosion Inhibitor
Protect your brilliant and toned coins no matter what type of storage container you use. Works with all metals. Metal SAFE block deposits an invisible protective molecular film on all metallic surfaces, and provides protection for 33 cubic feet of enclosure space (a 2 foot radius) for one full year. Each capsule has a shelf life of 3 years, and is kept sealed in its original polybag.