Single indoor station for expanding the Vistus door intercom system, item no. 515983 and 515984. Visual doorbell indicator: blue light frame around the talk and door opener button. 177 mm (7") color TFT display. The doorbell volume is infinitely adjustable. The silence button allows you to turn off the doorbell sound (e.g., during nighttime quiet hours) - a red light frame blinks as a reminder. With intercom function: communication from one indoor station to another within a residential unit. Only 22 mm flat surface-mounted installation. Connection for floor doorbell button with its own ringtone to distinguish between house and apartment doors.