Keep your gun safe dry and your guns free of rust, corrosion, and other moisture-related damages with the SnapSafe® Rechargeable Gun Safe Dehumidifier. Moisture-control crystals change from orange to green when the unit needs recharging for quick, noise- and odor-free visual notification. Simply recharge and dry out the crystals by plugging the unit into a standard 110V electrical outlet until the crystals turn orange again, indicating the unit is again ready for use.