Review on 🌬️ Optimized Guardian H910BL Cool Mist Humidifier: Extended Run Time, 210 Sq. Ft. Coverage, Ideal for Small Rooms, Ultra-Quiet, Filter-Free, Mold-Resistant Treated Tank by Brian Fisher

Not sure what they mean by 3.5 liters, I thought it meant litres, but it's probably more like 350 milliliters (which would be 0.35L) . Towards the end of the description it says the tank is .23 gallons, don't miss it! On a high setting the water will drain out at the end of the night and on a low setting little to no moisture will be released but it will stay on all night. It works like a blue night light if that's what you want. And it says NO essential oils in it, but honestly, at this size, what else is it good for other than as a diffuser?