Ideal for dry control of desiccator cabinets. Moisture is absorbed through the perforations in the aluminum case, which contains silica gel. This 2 x 4" canister maintains a safe level of humidity in 3cu.ft (0.8 cu. meter) area. When the monitor window turns pink, the silica gel is saturated. It can be regenerated in a 300 degreeF (50 degree C) oven in about 3 hours. The monitor window will be blue in color when recharged.