This Boveda 1-Step 75% Calibration Kit Features:

-Simply place your hygrometer inside the bag, close the zipper, and wait 24 hours. A perfectly-calibrated hygrometer will read 75% RH. If your hygrometer reads above or below 75%, adjust the calibration by the number of percentage points it is off from 75%.
-Completely maintenance free - no activation required. Easy to use.
-Bag Dimensions: 4.5-Inch x 9-Inch.
-Lasts approximately one year, good for multiple calibrations. Shelf life before opening is a minimum of 2 years.
-Produces an environment of 75-percent humidity

For any humidity sensitive product

Boveda can be executed in a full range of relative humidity levels (13-95%) to preserve the precise humidity atmosphere for any item with which it’s packaged.

Description:

How Boveda Works for Herbal Medicine

When do you use a 60 gram Boveda? Whenever it fits in your storage container. Boveda will never humidify beyond the RH on the pack, 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. 60 gram Boveda are commonly used in mason jars and large bags. They can last 6+ months depending on how often the container is opened, you'll know it's time to replace when the entire Boveda begins turning hard.

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 desktop humidor 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.

Note: Do not mix Boveda RH levels within the same container, and do not use Boveda in the same container with other humidification products. They will fight against each other and reduce the efficiency of the Boveda.