Four-Line Speakerphone model 984 features auto attendant and type 2 caller ID on each line. Does not require professional installation of key system unit. Each phone contains circuitry needed for features. Simply plug into existing phone jacks. Other features include digital answerer, duplex speakerphone, intercom and paging, 200 number directory and call log, volume control, three party conferencing, auto-line select, hold/flash/redial/mute, do not disturb, call transfer, convenience and headset ports.