Master Monitor - The JK-1MD is an open voice, color video master monitor with Pan/Tilt/Zoom controls that allows the connection of one single video door station and an additional sub monitor. The unit features a 3-1/2" TFT Color monitor, a TALK button for PTT or VOX activated communication, button for Pan/Tilt/Zoom control, Call button to call sub monitor, and button for brightness controls.