SHOTGUN Jr. Dehumidfiier stones are designed for Rifle case and safe sstorage. The dehumidfiier stones are made with patented absorption material that can be simply renewed by microwave within only several minutes. With the help of a color indicator that turns from White (Dry) to Blue (Wet),lets users easliy monitor the humidity level int he applied area, creasting a dry and anti-rust enviroment for your collections.