The Boveda 72% Two-Way Humidity Control Packs are designed in a rectangular prism shape with rounded corners, providing automatic operation for controlling humidity levels. This pack includes 4 packets and 1 resealable bag, suitable for use in airtight containers, glass jars, storage bags, and more. Made from wood and weighing 8.8 ounces, these packs are safe to touch and offer two-way humidity control, making them a convenient and effective solution for maintaining optimal indoor air quality.