... CONTACT ID,4+2 EXPRESS,4/2,4 /1 and 3/1 formats and is compatible with all systems commonly used ... Compatible with CONTACT ID,4+2 EXPRESS,4/2,4/1,3/1(10-40bps) protocal. 4. Easy for installation and ... call receiving format: CONTACT ID,DTMF 4+2EXPRESS, 3/1,4/1 and 4/2 pulse(10-40pps),caller id> caller ... call receiving format: CONTACT ID,DTMF 4+2EXPRESS, 3/1,4/1 and 4/2 pulse(10-40pps),caller id> caller ...