This was the second diffuser I got-- the first one was a different brand that didn't work so I tried this one. It works. However, unless you are right next to it you don't notice any difference in how the room smells. I've played around with how much essential oil I've added but that doesn't seem to matter. It does stay on until the water is out and the buttons function wonderfully, just doesn't diffuse as much as I was hoping for.