.Inbuilt 4 Line In card and 48 extension card , card can be extended up to 128 port for extension and 8 Line in
External Audio in and Music control
Programmable extension number as per your need, programmable welcome tone to caller, auto attendant, call routing if not picked up desired extension Four line trunk give possibility of adding FCT device so that SIM card can be used to get call along with PSTN lines, call waiting and holding on each call , Boss Override on Busy Extension
Caller ID for each extension , all extension can talk to each other at a same time .
Product Feature: 
* DISA Auto-attendant* Dial 0 or 9 for CO line
 * Operator Attendant* Select Desired CO line 
* Call Transfer* Extension password 
* 3-party Conference Call* Extension outgoing call class * Call Pick up* Outside ( CO ) Line Duration Time Limit 
* External and extension caller ID* Allow extension use appointed CO line * External music on hold socket System Feature Optional Feature * Self-extension number confirmation 
*  Power failure transfer 
* Bill, hotel software, function program by PC * Executive busy override 
* Extension number assignable freewill