Ideal for desiccator cabinets, making trays of loose desiccant obsolete. The silica gel inside absorbs moisture through perforations in the aluminum case. One canister maintains a safe level of humidity in 3 cubic feet of space. It has an unlimited life as it can be regenerated in a 300°F(150°C) oven. A monitor window shows blue when recharged and pink when saturated. Dimensions are 2"x4"x1/2".