Boveda’s patented two-way humidity control responds to ambient conditions by adding or removing moisture to affect the enclosed environment and deliver the pre-determined relative humidity (RH) level printed on the pack (58% or 62% RH, depending on your preference). When Boveda is completely dry, it will turn into a solid wafer—when there are very few soft spots left, you’ll want to replace it. It’s currently available in one size: 1 x 67 g (112 to 450 g).