The high capacity E-500 dehumidifier has been designed to absorb moisture from small, enclosed areas. It will help protect clothes and valuables from the damaging effects of mold/mildew and moisture rot. It is 100% renewable and needs no power to operate. Place the Eva-Dry E-500 unit in a closet or any small, enclosed space up to 500 cubic feet, and it will start to absorb moisture immediately. Spill and mess-free unit requires no batteries for operation. Color-changing crystals indicate when it's time to "renew" the unit. Renewal involves plugging into a well-ventilated space so that crystals can warm and release the trapped moisture as water vapor. Eco-friendly design is child and pet safe. 8"L x 2.5"W x 5.5"H.