Air-O-Swiss Travel Ultrasonic Humidifier:

It’s a little bigger than a Macbook Pro power supply, and twice as thick. It has a clever water reservoir, any .5 liter or smaller water bottle snaps into a fitting, and will supply 6-10 hours of vapor, depending on the setting.

Berlin apartments are as dry as a brush fire, so we also ran it all day in the living room, and even in a large room, it made the air so much more pleasant. Then we ran the Air Swiss all night for the baby, and again it performed perfectly. That’s day and night for 30-days non-stop; it’s built solid.

The only drawback is that there is a rather bright blue light that illuminates the vapor when the unit turns on, which changes to a red light when the water bottle is empty. If you’re a light sensitive sleeper, it might be an issue.

Source: Cool Tools