The Desco 13843 Desiccant Pack, 1 Unit, 2 in. x 4 in., 450 Count is a drying agent used to lower the moisture content of air inside a closed space, such as a Moisture Barrier Bag (ANSI/ESD S11.4 Level 1 and Level 2 Static Control Bags). Desiccant is packaged in fractional units in order to facilitate its usage with a variety of bag sizes. One full "unit" of packaged desiccant will absorb the following quantities of water at equilibrium with air at 77°F (25°C): 3.00 grams @ 20% rH and 6.00 grams @ 40% rH, when tested to MIL-D-3464.