The Eva-Dry Edv-500 Mini Dehumidifier is a dehumidifier that does not use power, but uses specialized engineered crystallized silica gel that is odorless, non-toxic and completely safe. Once the moisture is absorbed by the dehumidifier, it cannot leak or spill. These moisture meter crystals change from blue (when dry) to pink (when wet) to indicate when the unit needs to be renewed. The unit takes about 12-14 hours to completely renew. The Eva-Dry Edv-500 mini dehumidifier helps protect clothes and valuables from the damaging effects of mold, mildew and moisture rot. Six to eight ounces of moisture is absorbed depending on the humidity levels and this process should take about four to eight weeks. The crystals should be active for ten years if used correctly.