1. Three paragraph of computer operator's voice 2. Fsk/dtmf sender chip inside, co line cid can be transferred from one extension to another freely(need cid board, optional) 3. Co line monitor 4. Outgoing call restrict range 5. Trunk line transfer to trunk line,3-party conference call 6. Call splitting and call forwarding 7. Auto transfer to another when transfer to a busy extension 8. External music input 9. Use PC to program, compatible with cdx2000 PC manager system 10. Plastic case 11.32 group password 12. Upgradeable module design (from416 to 832) 13. Internal cid, alarm clock 14. Hi-efficiency safe switching power, back up battery(optional) 15.300 charge data can be stored(416-832) 16. Plastic case 17. Day/night mode with real time clock(208/308cp)(optional)