Restore and Maintain with the Global Leader in 2-Way Humidity Control. Place Boveda in packaging for precise Relative Humidity (RH). Choose 58% or 62% RH—a personal preference depending on the humidity level where you are. All Natural Salts and and Pure Water inside keep contents fresh for 2-4 MONTHS in airtight containers. Just replace when Boveda is rigid Boveda creates a monolayer of purified water molecules that naturally shield your products until use Resealable high-barrier plastic bag is factory sealed. Keep the zipper closed and you can expect unwrapped Boveda to stay fresh for up to 2 years before you're ready to put them to use