Hydrosorbent Dehumidifiers offer additional long-term protection for your coins by removing moisture from the air, preventing condensation, rust, mildew, corrosion and spoilage. Dehumidifiers come in many sizes and can protect small boxes and safes or larger safes, cabinets, vaults and closets. Dehumidifiers last a life-time and can be reactivated in any oven. Each Hydrosorbent Dehumidifier has a built-in indicator card that turns from blue to pink when the dehumidifer needs reactivating.