D'Addario Humidipak Control System PW-HPK-01

The D'Addario humidipak control system uses patented gel technology to release water moisture when your guitar needs it. Its automatic and easy! This system is best used when storing your guitar in the case. Place two gel packs in the soundhole pouch and one gel pack in the headstock pouch. That's it! Depending on the ambient humidity in your area, these packs can last between 1-3 months.