Features 1) Upgradeable module design 2) Auto detect CO line status 3) Transferred CID system 4) Twice caller ID (optional) 5) Three paragraph recording 6) CID or voice announcing EXT number 7) Day / night mode 8) Private password 9) Door phone interface 10) Outgoing call restrict range 11) Authorized dialing / six level call restriction 12) Flexible outgoing call restriction 13) Distinguish ringing tone for EXT / CO line / door phone 14) Alarm clock 15) Auto / operator mode 16) CO line booking 17) CO line hold 18) Trunk line transfer to trunk line, 3-party conference call 19) Call transfer and call pick up 20) 40 group speed dialing 21) Broadcast call 22) Flexible EXT number 23) External music input 24) Real time clock 25) High efficiency safe switching power, back up battery interface 26) CO line connect to EXT directly while power off 27) PC interface, use with PC charge software 28) Keep 1400 charge data while power off 29) Remote programming Specifications: 1) Extension: 8, 16, 24, 32 2) External line: 2, 3, 4, 8 3) Commutation line: 8 4) Power supply: AC 110 - 240V 5) Power: ≤ 20W 6) Storage battery pressure: DC 48V 7) Charge current: ≤ 30mA (optional)