SLEEP MODE: The display and 7 colour changing tank lights can be turned off to ensure a good night’s sleep with no disturbing lights. EASY TO USE: Simple, easy-to-use, one-touch control. Low Operating costs Low 24W energy consumption, instant relaxing aromatherapy, providing a restful sleep. Refilling is simple with this top filling water tank. AROMA FUNCTION: Improved design to allow essential oils to be added within the water tank to disperse your desired fragrance providing a calm and relaxing environment. ULTRA-EFFICIENT, LONG-LASTING DESIGN: The PureMate Cool Mist humidifier is the best of the best. Equipped with a large 4 litre water tank and wide mist release, this humidifier can humidify rooms up to 40m²! One tank will last for up to 40 hours of continuous use on low setting. COOL MIST & QUIET AS A WHISPER: The gentle, cool mist provided by humidifiers is known to deter growth of harmful bacteria, dust mites; and relieves cough, irritated nasal passages, and throat. Cool mist keeps nasal passages, sinuses, and skin hydrated in hot, dry weather.