The Desivent KDV300 mini dehumidifier is a clean and simple way to control excess moisture in small areas like storage cases, cupboards and wardrobes. The cassette contains Hydrium™ crystals which absorb moisture. The KDV300 dehumidifier doesn't require a power source to operate. This makes it a very versatile little unit and ideal for places like cars, caravans, boxes in garages, display cases in museums, clothes drawers and any other confined place where a power supply isn't readily available. When the crystals have soaked up the maximum volume of moisture and are exhausted, you plug the mini dehumidifier into the mains in a ventilated area and it dries out. This takes approximately 10 hours and costs 1.5pence! When dry the indicator on the front of the unit is blue and when the unit is full to capacity the indicator turns pink. Unlike salt based dehumidifiers that can only be used once and that have messy drainage trays to empty, the KDV300 is rechargeable so can be used again and again. The KDV300 is non-toxic, odourless and safe unlike salt based dehumidifiers which normally have an “Irritant” warning label.