Boveda not only knows 2-way humidity control for packages and containers, they invented it. It’s well known in science that certain salts mixed with water will naturally regulate humidity. They just patented the way that made it practical for packaging. All other packaging inserts either add moisture or remove moisture.
Only Boveda does both, monitoring the RH (relative humidity) inside the container and regulating to the specific RH engineered into the Boveda. Available in three sizes and humidity levels, Boveda is the only company in the world that can solve your intermediate moisture need and maintain the ideal moisture content of the items inside your container.