The fact is that this equipment needed to operate two round cells type LR44. That is unfortunately not here in the product description, yet in the ratings. On the contrary, it is alleged, these batteries would be around.
The truth is (as of 8.6.2012): these batteries are NOT included. So I can not (yet) use the device now. Also the associated battery compartment is closed on's dilettantischste: instead of using a simple snap closure (which would certainly be sufficient completely), are two totally committed loopy screws that turn but have a very poor Phillips and also made of very soft iron - overspeeding while attempting to open flap, is as good as guaranteed.
So a complete package is far from being able to get by me 5 stars. I can test the actual function only when I finally get this button cells, which I would have ordered, of course, if only a single word would have pointed out to me.
But there is only once a star, there is really nothing more annoying than as a primitive product design and the necessary batteries (which in addition also are still quite exotic) not settle. From me so very big warning: just so it does not install, it lacks the necessary batteries.