Protects your precious instrument from drying out. Ideal for storing instruments in particularly dry, cold seasons or in extremely dry rooms. This humidity control material for classical guitars provides the right amount of humidity by simply wetting the moisturizer and inserting it into the sound hole, preventing wood deterioration due to dryness. The moisturizer can hold up to 20 times its own volume in water and is made of a material that retains the absorbed water, preventing the guitar from drying out for a long time. It can be reused by simply wetting it with water, making it cost-effective. *The effects of this product are for preventative and emergency use only. We recommend that you permanently maintain the indoor humidity at around 50% and the temperature at around 20°C. *Please be sure to read the guitar breath instruction manual.