Reliant Systems offers selective calling, open-voice style master stations with the capacity of up to six stations in any combination. Incoming calls from a sub- or door station are annunciated with a momentary electronic monotone and LED, remaining lit for approximately twenty seconds. Communication at the calling master is press-to-talk, release-to-listen, while the user at the receiving station speaks hands-free. The operator can selectively communicate with any other sub- or master station in the system, although privacy features on on both ends prevents eavesdropping from the master station.

Aiphone