Siedle Basic video set in bus technology with the functions of calling, speaking, viewing and door opening. Number of call buttons: 2 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 850-2-. E) . 2 Siedle Basic video indoor stations (VIB 150-.) . Set power supply unit (SNG 850-.)