Featuring an adorable, child friendly animal design, the bpa-free crane ultrasonic cool mist humidifier provides up to 24 hours of moisture on medium setting from its removable one gallon water tank. suitable for rooms up to 250 square feet in size, this compact unit is energy efficient and uses ultrasonic technology to add soothing moisture to the air. crane"s cool mist humidifier provides a non-medicated relief for dry cough, nasal congestion and cold and flu symptoms. crane humidifiers are a great gift for baby showers, birthdays and holiday season. this humidifier does not require a filter to operate.