Easy to use, simply unwrap, add PG Solution and place the humidifier in your humidor. Slow, steady release of constant humidity of 70% . Clear polycarbonate cases house crystal gel saturating 450 times their weight with XIKAR PG solution! Magnet attachment system holds the unit firmly under the lid of your humidor. 3 1/4in. across, 3/4 in. thick. Maintains up to 100 cigars in a volume of 850 cubic inches at 70%.