It doesn't do the automatic turning on thing, but it did the automatic switching off -- however it didn't wait until I stopped the bike, so I was happy when it stopped doing that too after the first 10 minutes.
This item fits on mountain bike/car valves, but it comes with a plastic bit you can screw on it and than you can attach it road tires too. That extra bit has a piece of plastic in the middle that I needed to knock out with a screwdriver and a hammer to fit, but no biggie. (sorry for my poor vocabulary:S)
I really only tried it one evening in town with streetlights, but it looked nothing like those circular patterns on the picture, it was more like little lights going around. Maybe if you ride your bike with it in bitch black very, very fast it will look like on the pictures, but that probably won't happen.
But anyway, it still is bright enough to give good visibility from the sides --which is the point after all-- and it's cheap, so I still recommend buying it.
