The Air Innovations model 509 ultrasonic, cool mist, smart humidifier is one of the top rated, longest running, and most versatile humidifiers available for its size. Key Features: 1.4 gallon tank that runs for a full 70 hours on low (almost 9 nights of sleep) and is completely silent when running. Powerful enough to add humidity to large rooms up to 400 sq. ft., with a programmable built in humidistat that monitors and maintains the humidity level you set. The entire unit and base are made of antimicrobial plastic to prevent bacteria, mold, and mildew growth and it comes with a permanent ceramic filter to help trap impurities in your water. Unlike Vicks, Crane and Essic humidifiers, it also features a 360-degree rotating mist nozzle that helps direct the moisture where you want it. Color: White.