I initially had concerns that it could cause a malfunction. However, the bell is working properly when the batteries are full. For that is such a problem: The batteries in the receiver (the large, semicircular part) I have about every 5 months to exchange (3 AA batteries). The battery in the button I had to now exchange recently, has thus held approximately one year. Unfortunately, you do not know when the batteries are empty, but must repeatedly between testing itself. Otherwise get the not with so quickly. Here it is also not clear which batteries have now subsided, so you'd like to quickly replace all batteries. At a minimum, which is quite expensive in the switch, because no standard size. To me it's already happening, that people have sturmgeklingelt, and I have not opened because the batteries are dead.
Otherwise, the ringtone to my mind is hellishly loud. While there are different ring tones from which you can choose. But they are all equally loud.
Four stars because you have to guess when the batteries need to be replaced, and because the ringtone is simply loud. Otherwise, however, the supply is functioning as it should.
UPDATE: In the fall of 2013, Gong has then given up the ghost. At first I had only thought I had the battery in the button Replace, which I did at first (quite expensive). But unfortunately it was not. Times did the bell, then again not. Since it was unreliable, and one of my visits so stopped in front of a locked door, I have replaced the unit.
