Siedle Basic video set in bus technology with the functions of calling, speaking, viewing and door opening. Number of call buttons: 1 Each basic set can be expanded to include selected door and indoor stations, as well as switching functions and a telephone connection. Scope of delivery: . Siedle Basic video door station (CV 850-1-. E) . Siedle Basic video indoor station (VIB 150-.) . Set power supply unit (SNG 850-.)