The Integra Boost Humidifier 4 Gram Pack 72% is the maintenance-free, eco-friendly way to ensure your favorite cigars stay fresh. Its responsive Integra BOOST (TM) system quickly releases or absorbs moisture as needed to ensure your humidor maintains its ideal humidity level. To use, simply place the pack in your humidor along with the Replacement Indicator Card. When the dot on the card turns blue, it’s time to replace the pack. The 4 gram pack is perfect for use in cases, pouches and jars.