About this item: EFFECTIVE RELIEVE DRYNESS - Ourair humidifiers are capable of emitting up to 280ml mist per hour and quickly elevate humidity up to 50%-80%RH to effectively relieve dryness and symptoms of cough and dry throat.  And with its high mist volume it is capable of covering a large room of 350ft²/32㎡, keeping the whole room at a wholesome humidity level. LARGE WATER TANK - With a 4L extra large water tank, Our Air Humidifier could emit fine mist to the air continously for 30 hours, lasts up to 3 nights with a single refill.  No need to refill water frequently.  It is ideal for bedrooms, baby rooms, living room, offices, and plants! SAFE & QUIET - The air humidifier is made from durable BPA-free materials, and features a safety setting for automatic shut-off when water shortage.  No worry about safety when use it overnight.  Utilizing ultrasonic technology, our air humidifier works extremely quietly at night.  You can fall asleep peacefully without being disturbed by noise.  So the humidifier is also a good choice for bedroom or babyroom. EASY TO OPERATE - The cool mist humidifier only has one operating knob.  You can switch on/off or adjust the mist output simply with a mechanical knob.  And with large opening top-fill design, you can refill or clean the water tank easily.  Simply remove the upper lid and pour water from the top. SPECIAL AROMA BOX - Unlike conventional humidifiers, OurHumidifers have a special built-in anti-corrosive aroma box to allow safe use of essential oils (avoid corrosion hazards), diffusing them into the air together with the water mist, making your room smell fresh while humidifying.