**Boveda 67 gram Humidipak 62% - 2 Way Humidity Control [10 Pack]** How Boveda Works Scientifically engineered to maintain a precise relative humidity of 62% (RH) in an enclosed space. Boveda will never humidify beyond the 62%, so there's no such thing as "too much". You want to think in terms of using at least the minimum because the more you use, the more efficient Boveda works and the longer they last. You'll know it's time to replace when the entire Boveda begins turning hard. Simply place the correct number of Boveda inside your container to maintain a precise 62%. Each Boveda 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 container Boveda maintains a predetermined level of (RH) by releasing or absorbing purified water-vapor, as needed, through the membrane. Boveda provides the cleanest and most purified humidity of all other products available on the market today. Visit Boveda's website to find out more here . Boveda 62% 67gram Specifications Suitable for 450g of herbs 67 Gram inside a sealed plastic bag Stabilises at a consistent weight and burn Unlocks colour, aroma and flavour, while locking in herb Lasts months in a sealed container, replace when it gets hard Size 13 x 9cm Shelf life of one year in original packaging