If the water added over max line, the mist will be very thin(less water, more mist) Please don##x27;t touch the internal ultrasonic wave vibration board inside of the water tank directly with your hands. If the ultrasonic wave chip was polluted, it may cause error action or default. It will run for about 8 hours. Add a few drops of your favorite essential oil (NOT INCLUDED) to enjoy wonderful aromas throughout your home.Humidify the air, breathe easier, and relieve cough and sinus congestion due to colds, allergies, and flu. Reduce odors in your house from cigarettes, cooking, and pets. Whisper-Quiet Ultrasonic Operation - humidify your living space to prevent dry, stuffy air and flu/cold germs infecting your loved ones. Prevent dry and chapped skin in dry winter months. You may return items in its original condition within 30 days. The item "KBAYBO 500ml Cool Mist Humidifier Ultrasonic Aroma Essential Oil Diffuser wit" is in sale since Monday, May 29, 2017. This item is in the category "Home & Garden\Home Décor\Home Fragrances\Essential Oils & Diffusers". The seller is "mightygalaxy" and is located in US. This item can be shipped to United States.