Lockdown 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. Each bag contains individually wrapped 40g silica bags and each bag contains an indicator card that shows when it's time to recharge. The silica gel changes in color from blue to pink when it needs to be recharged. Lockdown silica gel is ideal in everything from vaults to electronics storage. Recharging can be done easily in your home oven.