Easy to install wireless door bell system with 8 melodies for choice the ringing display functions optically via three blue leds the system is expandable with an additional sender zb order no 61 08 04 and with several recipients zb orderno 61 07 96 order 61 07 97 the system has an automatic training coding the connection is possible at available door bell the ring tone is switched off for rest phase control light informs about the battery status