The Drymistat Tube is the perfect humidification solution in keeping your cigars fresh without taking up space in your humidor! Take all the guesswork out of caring for your cigars. A single tube is packed with special absorbing crystals that swell up when you add water to them and shrink in size when they require refilling. Every 1-3 months when the crystals shrink in size, remove the perforated cap and simply add water to the "Fill" line. Stand the tube vertically for 5-10 minutes or until the water is absorbed, press the cap back in place and return to your humidor. Each tube maintains a perfect 70% humidity level per 25 cigars. Larger cigar collections will likely require additional tubes.