The Moisture Muncher Drying Agent performs one simple task - absorbing surrounding moisture in the air. This package is vapor resistant and contains 3 - 1 unit packs of drying agent. Once you open the plastic bag, it starts absorbing. Put one of these in your dry box or camera box to stop moisture from attacking your expensive gear.
These are re-usable - you can reactivate them by heating them - then use them again and again.
Note: These measure about 2 x 3 inches, and 1/4 inch thick. These are not the ones for inside your underwater housing. For that application, get a Anti Fog Dessicant Cap package.
Please be careful not to drop one of these into the ocean, as it might soak up all the water, and then there would be no place for the rest of us to dive! And if you believe that, please don't use life support equipment.