Safe and nontoxic, Eva-Dry is a natural defense against moisture and mildew in larger places. Fight dampness in boats, safes, RV's, and big closets. Works in a 500 cu ft area and lasts approximately 30 to 60 days before renewing. Renewable Eva-Dry dehumidifiers are filled with silica gel, a very thirsty substance. Odorless silica beads absorb many times their weight in moisture and lock it in so water can't leak or spill out. When the Eva-Dry is full you renew the silica inside by plugging the unit into any power outlet. Heat gently releases water vapor in a few hours. When the indicator is blue again, Eva-Dry is renewed and ready to go back to work. You can repeat the process for up to 10 years. Reduces allergens and eliminates odors. Spill and mess-free. Absorbs humidity silently. Operates without electricity or batteries. Simply renew when indicator changes color. Uses natural silica gel crystals. Child and pet safe. Nontoxic, colorless, and odorless.