I bought two of these, then when they arrived discovered they take unfamiliar batteries (ever hear of 18650 batteries? I hadn't). So I ordered those and when they arrived two days later found that the battery case doesn't close. After days of fussing with the batteries I discovered that there are _two kinds_ of 18650 batteries, one with a flat top and one with a button top. I had bought the button top, which are 2 mm taller than the flat top. This device requires flat-top 18650 batteries, which is probably why the battery case won't close. Am I going to try again and get the flat-top 18650s? No, because at this point I've already bought a competitor's model that actually works right out of the box _and_ includes plenty of little squeezy bottles full of fog juice.