English Market Selection present this ingenious Humidity Control Pack A sachet containing Crystal Gel & Propylene Glycol. On the face of the pack a handy gauge changes colour to inform the user of the accurate humidity. Simply peel the foil and put in your humidor, bag or carry case. Now you can rest assured your cigars will remain in optimal condition. Another great use is with dry cigars, just pop the Humidity Control Pack in a sealed bag with your cigars for a couple of days to revive them.