4 line GSM Wireless Terminal 1)lock card,lock terminal ... )support GPRS 4 line GSM Wireless Terminal Unique Functions 1,GSM cellular network outgoing.2,GSM cellular network incoming.3,DTMF Caller ... billing meter. (Optional)Technical Specifications1,Work frequency: GSM 900MHZ/1800MHZ or GSM 850/900/1800/1900MHZ2,Power: ≤2 W3, ... 9,Insertion loss: ≤0.5dB 4 line GSM Wireless Terminal/Fixed wireless terminal