chord sing originally
Chord ringers,IP swift,keep secret dialing
4 music key tones
chord music beat color lamp of incoming telegram
predial mumbers,off-hook,incoming backlight
43 groups 12digits incoming numbers
9groups 12digits outgoing numbers
3groups alarms clcock function
FSK/DTMF dual systems
Thunder protection and Anti-EMI
wiretap protection,long distance key lock
voice talking CID,transfer function