Features 1、INCOMING CALL AND OUTGOING CALL FUNCTION: Telecom check line calls 50 groups and outgoing calls 16 groups. And call time record. 2、MUSIC BELLS CAN BE SELECTED: Telecom check line 16 kinds of music bells are available, software setting P and T, no need to switch. 3、CALLER ID: FSK/DTMF dual system caller ID (press **# for system conversion). At the same time, the keys are sensitive without delay. 4、MULTIFUNCTION: Telephone dedicated check line adopts the functions of checking incoming and outgoing call numbers, calling back, and deleting. 5、DETECTION FUNCTION: The telephone survey line machine can detect whether there is a problem with the telephone line. Specification Item Type: Telephone Material: ABS Model: S-1 Function: Caller ID, FSK/DTMF Dual System, Callback, etc. Package List 1 x Telephone 1 x Adapter Cable