I bought this after looking at more expensive ones in my local garden centre. This one is easily as good quality if not better. It comes well packaged, with power adaptor, clear instructions and a little measuring cup. It's really easy to use, you just fill the measuring cup with water to the fill line, lift up the top of the diffuser and pour the water into the well, then just add a few drops of essential oil (I added gingerbread scented oil!), put the top back on and press the on button.
I starts up virtually instantly and you'll see the puffs of scented steam (although cold steam so it's safe) coming out the little spout. The diffuser can work permanently on, or on a built auto shut off timer. The LED lighting is a nice touch and can be set to a particular colour or can be left to automatically change like a mood light.
Overall, really good quality diffuser, well worth the money, works really well.