Desiccant Dryer Moisture Control Home and Office Safes w/Humidity Indicator Card - Up to 7 Cubic Foot Safe Use these desiccant packs to knock down humidity in home and office safes. Includes FREE humidity indicator card. This item contains qnt (12) desiccant packs. The 12 desiccant packs are sealed in plastic bags for shipment. This item is appropriate for up to a 7 cubic foot sized safe. A rule of thumb for storage is to use 1 Unit of desiccant for each 0.6 cubic feet (90 cubic inches) of enclosed space. These Tyvek enclosed desiccants are Food/Pharmaceutical grade so you can be confident they won't damage the contents of your safe. When bags are saturated they may be reactivated by carefully heating in a convection oven set to true convection mode. IMPORTANT: If bags can "see" a red-hot radiant heating element the Tyvek will overheat and melt. Heat to 245 degF for 16 hours. Note that the Tyvek package melts sharply at 275 degF. If the bag melts you have overheated it.