Features: 1) CO lines: 2 - 4 2) Extension lines: 8 - 16 3) Multiple communication lines 4) Normal transformed power 5) Switch power (optional) 6) Backup battery interface (optional) 7) Power failure transfer 8) External line caller ID 9) Transfer caller ID 10) Intercom caller ID 11) Auto-attendant (DISA-12s, one paragraph) 12) Outgoing message recording 13) Auto IP dialing 14) Internal music on holding 15) Door bell and door opener (optional) 16) Remote programming 17) Memory protection while power off 18) 11-chord melody music selectable 19) Automatic / operator mode 20) System password 21) Flexible extension number assignment 22) Multiple dial-out modes 23) External line group 24) Duration control, call pickup 25) Outgoing call transfer 26) Call transfer 27) Call forwarding 28) Flexible coding (change extension number) 29) Do not disturb 30) Automatic EX reporting 31) Flash time choice 32) Ringing assignment 33) Call restriction 34) Three way conference 35) CO line transfer to CO line 36) Call all extensions 37) Specific CO line dialing 38) Ring identification 39) CO line booking 40) CO line reservation 41) Operator setting 42) CO monitor