It is worth knowing that this Gong in existing doorbell systems (intercoms not) can be integrated and thus manages the station without batteries. According to the manual, the batteries in the receiver - are possible 4x R6 in the supplied adapter approximately 1 year or R14 about 5 years. That would be considerable. The flash can be turned off or use together with the ring signal. All in all a very well thought-out product in which this price is justified. A cheaper Gong abolished the distance of 20 meters by 2 glass / steel walls do not, the Grothe-Gong creates problems.
