The installation in a bell system is very simple, although not described in the instructions. To this end, the two screw terminals on the back with the names "L" and "N" on the permanently installed push buttons must be bridged. So completely without bell transformer / external voltage. For this, the batteries must be inserted, possibly also goes a USB power adapter (if I have the appropriate review correctly understood). The dubbing on the internal memory is very easy for some computer experienced. Before that, cut out the desired sounds, so that the ring tone is not too long, and there you go. Possibly bring even with MP3Gain all been played sounds the same volume. My current sounds are from parts: Batman, Benny Hill, James Bond, Sindbad, play me the song of death, Wolfgang Hart Mayer (ARAL advertising) :-)
