They are just like the pictures on the MITB website, come in a pack of two, with two plastic adaptors to go from schrader to presta valves. You just unscrew the aluminium housing, remove a little plastic thingy from the battery, screw it back, and you're good to go!
It's motion sensitive, so as soon as you move, it switches on. Changes colours and flashes randomly. And they're bright!
See pics, which don't do them justice; they look much better in real life.
Once again, great price, great product and fast free delivery.