This is perfect for small to medium sized rooms like a bedroom, dining, bathroom or lounge room, especially if they are air conditioned or in winter which makes the air dry. Keeping your living space humid helps prevent colds/flu and congestion. It can also prevent dry and cracked skin. Three Settings toggled by the Mist button (Green/Red/Off): 1.Green – intermittent mist (Mist 30 seconds and Pause 30 seconds). 2.Red – continuous mist. 3.Off – You may use it as a color changing light without mist. [Specifications]: 1> Material: Upper parts PP. 2> Capacity of water tank: About 100ML. 3> Noise Level: less than 35 dB. 4> Input power: AC100-240V 50/60HZ. 5> Most advanced ultrasonic technology: 2.4MHZ. 6> Working time: 3-6 hours. 7> Automatic shut off safety system when waterless protects the product from being burned out. Keep essential oil 100% natural. [Package Contents]: 1 x Aroma Diffuser, 1 x Charger Adaptor, 1 x measuring cup for filling water, 1 x User Manual. Features: 1.Relax – fill the space it was with a lovely fragrance that can lift your mood and relieve stress from Stressful and tired day, perfect for Masking stubborn smoking and pet odors, get great and peaceful nights’ sleep surrounded by the aromatic fragrance 2.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 Auto shut off when water runs low – adds to safety, energy efficiency, and peace of mind- especially for use at night 3.LED light – 7 color changing lamps for your choice, can be turned off entirely, or can be set to one fixed color 4.Content: 100 ml; wall charger length: 1.7 M; size: diameter=3.93 in, height=5.51 in; weight: 11 oz material: PP hard plastic working time: 3 hours in continuous mode, 6 hours in intermittent mode We only have EU plug and US plug. If your country use other types of plugs. Please contact us and we will send you the adapter. Question: How long does this run for? Can I use it overnight? Answer: You can use it safely overnight. It will probably run about 4 to 6 hours and then shut off automatically. It will do the job while you rest. Hope that answers your question. Question: Parden my ignorance, but can you is this as a humidifier without oils? Answer: I guess you could. However it would be a rather small reservoir to actually do anything.