Designed in California. 1.1 GALLON/4.5L WATER TANK: The large capacity water tank can hold 1.1 Gallon/4.5L of water and support up to 36 hours of continuous use in Mist Level 1. Mist output can reach up to 250 ml/hr and cover normal size roomDISPLAYS EXACT HUMIDITY: a sensor, included on the cord, diligently reads the environment to gauge accurate humidity levels. Check the LED display to easily find out the relative humidity (%RH)ADJUSTABLE MIST LEVELS: Customize your mist with the humidifier different options! Select a humidity level (30-80%RH), a mist level (from 1 to 4), or auto mode, all with touch panelCONVENIENT AUTO MODE: Want your humidifier to do the thinking and work with your environment? Auto mode adjusts mist output based on %RH feedback from the sensor to keep your room comfortableINSTANT AROMATHERAPY: open the aroma box and drop in essential oils to create a fragrant and relaxing atmosphere. Note: DO NOT add essential oil into the water tank and base, or it will cause leakage and stop workingQUIET OPERATION: Ultrasonic air diffusion keeps things whisper-quiet-it produces very low noise. It is so quiet that you even can hardly hear it is onEASY TO REFILL AND CLEAN: A 3-inch-wide tank opening makes it very easy to refill with less risk of spills. You can also fit a soft brush or rag through the opening to wipe down the inside of the tank and prevent bacteria buildup. Note: DO NOT let water enter the air vent while cleaning the humidifierBUY WITH CONFIDENCE: Safety guaranteed as auto shutoff when it detects no water; 1-year buyer assurance (with a free option to extend it by 1 more year) and lifetime support from Levoit