The Eva-Dry E-333 Renewable Wireless Mini Dehumidifer uses renewable silica gel technology that doesn’t need batteries or power to work. It works in areas up to 333 cubic feet and has a capacity 4-6 oz, after which the indicator window will turn from blue to pink, meaning it is time to keep the device fro 10 hours in a well-ventilated area to restore it to its original condition. This needs to be done every 2 to 4 weeks, but it depends on the level of humidity. The humidifier doesn’t leak or spill any liquid and has a life span of almost 10 years with a 5 year warranty.