CyberData's new SIP Talk-Back Speaker enables two-way conversations in settings such as classrooms, offices, medical facilities and clinics. By use of remote call button (sold separately, part# 011185), calls to a predetermined extension can be initiated from the room with the speaker. During the active calls, the LED light on the switch can be programmed to blink to show call activity. Alternatively, a call can be placed to the speaker to initiate either a page or two-way conversation.CyberData's new SIP Talk-Back Speaker enables two-way conversations in settings such as classrooms, offices, medical facilities and clinics. By use of remote call button (sold separately, part# 011185), calls to a predetermined extension can be initiated from the room with the speaker. During the active calls, the LED light on the switch can be programmed to blink to show call activity. Alternatively, a call can be placed to the speaker to initiate either a page or two-way conversation.