Place the unit with the indicator card down, occasionally examining the card. When the center circle turns pink reactivate the unit as follows: Remove the bag of silica gel granules from the unit and place the bag in a vented 240 degree F oven for at least 3 hours. Replace the bag in the unit. Please note that it may take several hours for the indicating circles to turn blue again.After reactivation is complete and the unit is cool enough to handle, return the unit to the enclosed space you wish to protect immediately. If you leave the unit in the open it will rapidly adsorb moisture from the surrounding air.