Hornady Dehumidifier Canister. When the moisture control crystals turn pink recharge unit by placing it in the oven. Unlimited recharges ensure a lifetime of use.Protect firearms and other valuables from rust and corrosion. Desiccant crystals change color when canister needs recharging. Recharge canister by placing in a 300F oven until drying granules turn blue (up to 4 hours). Unlimited recharges no batteries required. Specifications for Hornady Canister dehumidifier: Manufacturer: Hornady Color: Black Package Contents: Hornady Canister dehumidifier Hornady 95902: Dehumidifier Canister