The JM-4HD is a video sub master station for use with the JM-4MED master station. A maximum of 7 sub master stations can be used in the JM Series. The JM-4HD offers a 7 in. color touchscreen LCD and allows for handset (duplex) and hands-free (VOX) communication. This unit is equipped with a door release button for the user to allow visitor entry. The JM-4HD is also equipped with PTZ and brightness controls, giving the user control of the door station camera angle and camera lighting for better visibility. The JM-4HD connects to either the master station or JM-8Z distribution unit using CAT-5e/CAT-6 cable.