Slant Fin GF-240 1.9 Gallon Germ-Free Cool Mist Evaporative Humidifier Exclusive germicidal process using ultraviolet light (independent laboratory tested) Humidifies a closed room up to 400 square feet in size Cool Moisture Humidifies room with comforting mist that is virtually 100% free of bacteria, molds and spores Safer for allergy and asthma sufferers