Main Features: 1. Switch power (optional) 2. Backup battery interface (optional) 3. Transfer caller ID (optional) 4. Intercom caller ID (optional) 5. Auto-attendant (DISA:10s one paragraphs) 6. Auto-attendant (DISA:20s one paragraphs) (optional) 7. Auto/Operator mode 8. Auto IP dialing (optional) 9. External music input on holding (optional) 10.Doorbell & door open function (optional) 11.11 chord melody music selectable, auto select daily ((optional) 12.CO line transfer to CO line (optional) 13.Wireless terminal board (optional) Basic Functions: 1. Multiple communication line 2. Normal transform power 3. Power failure transfer 4. External line caller ID 5. Internal music on holding 6. Remote programming 7. Memory protect while power off 8. System password 9. Multiple dial-out mode 10.External line group 11.Call duration control 12.Call pickup 13.Outgoing call transfer 14.Call transfer 15.Call forwarding 16.Flexible coding (change ext.No.) 17.Do not disturb 18.Automatic Ext. reporting 19.Flash time choice 20.Ringing assignment 21.Call restriction 22.Three way conference 23.Call all extensions 24.Specific CO line dialing 25.Ring identify 26.CO line booking 27.CO line reservation 28.Operator setting 29.CO line monitor