Boveda 62% RH 2-Way Humidity Control, 67g, Large, 4 Pack Set of 4 individually overwrapped large 67 gram packs Lasts 3 months in most humidors 2-way humidity control, with accuracy of plus/minus2% RH Preserve your medicinal herbs, flowers, and cigars Curing and storage of your herbs and tobacco can only be preserved properly when humidity is controlled