... :Basic is 4 Lines 16 Extensions.Can be up to 8 and 64 respectively at most. Size:485X300X110(mm) Group Phone ... the function,system can monitor all of Co.Lines and Extension Status,also can monitor,program,revise and call charge account ... Sections 78s Outgoing message(can be up to two routes);8.Voice Extension number;9.Automation Answer Mode and group ringing;10 ...