This cube contains 12 individual Boveda, each of which is wrapped in a plastic overwrap to keep them fresh until you’re ready to use them. Shelf life of Boveda left in their overwrap is 2 years.60 gram Boveda provide hassle-free maintenance of full-size humidors and Humidor Bags. Every Boveda RH is accurate to +/- 1% in an air tight environment, which humidors are not. It’s common that the actual RH of your humidor will stabilize up to 5 points lower than the Boveda RH you’re using, due to humidor and ambient dryness.Unlike distilled water and PG solutions with sponges/gel/crystals/beads that will impart unwanted flavors on your cigars, Boveda’s reverse-osmosis membrane only releases pure water vapor and Boveda will never damage anything through direct contact.