Quicklime's main ingredient is calcium oxide (CaO), and it is a moisture adsorptive desiccant. From the chemical equation aspect, its hygroscopic rate can be 32% of its own gravity regardless of the outside temperature. For a physical adsorptive desiccant, this property produces more economical effects under the protection of low-moisture condition. In addition, it has strong water adsorption capacity and has no problem with adsorbed water vapor being released. Its moisture adsorption capacity can be determined by how much substance changes from granules to powder.