I have found that it does not work nearly as well when compared to traditional "spray on" insect repellent. As stated in previous answers, it is quite expensive to maintain- with many refills and battery replacements. I suggest not purchasing this item.
It kinda does. I have my own and it works pretty well, but I've found that because it has to point away from you, it isn't all that effective. Also, its really pricy, especially for refills which you need quite often if your outside a lot like me.
Yes actually they do but you have to bye refills a lot depending on how much you use them and if you forget to close the vent thing it gets really expensive to use because the refills aren't that cheap.