Lockdown Rechargeable Silica absorbs moisture from the air inside a vault or storage area preventing condensation mildew and rust from damaging valuable firearms. Crystals change color once fully saturated and can be easily recharged in the oven. – Absorbs Moisture From The Air – Individually Wrapped 40 gram Silica Bags – Indicator Card in Each Wrapper Shows When It’s Time To Recharge – Ideal for Handgun Vaults and Ammo Cans – Recharges in the Oven – Changes from Blue to Pink When Recharge is Needed