Snap safe's rechargeable gun safe dehumidifier absorbs humidity and prevents rust or mildew in gun safes, closets, pantries and other enclosed areas.Moisture-control crystals change from orange to green, indicating when the unit needs recharging.Dry out and recharge the crystals by plugging into 110v electrical outlet until crystals turn orange again. Effective in spaces up to 333 cubic feet. Mfg: Snap Safe
