Includes JK-1MD master indoor station, JK-DA surface mount audio/video door station with call button, power supply * Kit can be expanded to 2 indoor video stations with addition of JK-1HD sub station * Only 2 wires needed from front door station to indoor station, for quick and simple new construction or retrofit installation * Hands free or "push-to-talk" mode on indoor stations * Wide angle 170 degree CMOS video camera with 525 line resolution