5 Pack of 8 gram Boveda 72% Humidity Packets. The world's first 2-way humidity control for herbs, travel humidors and tobacco jars. Each Boveda packet consists of a specially prepared saturated solution of pure water and natural salt. This saturated solution is contained within a water-vapor permeable “reverse osmosis” membrane. Within a closed desktop humidor Boveda maintains a predetermined level of (RH) by releasing or absorbing purified water-vapor—as needed—through the membrane.