Features: 1.Easy to install. No need to invest in ground wire line, use GSM mobile phone SIM card. 2.Support international and domestic, local, fixed/mobile voice services. 3.Do not change the old dialing habits, the same as ordinary telephone landline operation habits. 4.With a reverse polarity signal, you can access the meter or use the computer meter. 5.Built?in watchdog duty circuit, automatic detection of equipment operating status, automatic restart failure. Specification: Features:_x005f_x000D_ _x005f_x000D_ Easy to install. No need to invest in ground wire line, use GSM mobile phone SIM card. _x005f_x000D_ Support international and domestic, local, fixed/mobile voice services. _x005f_x000D_ Do not change the old dialing habits, the same as ordinary telephone landline operation habits. _x005f_x000D_ With a reverse polarity signal, you can access the meter or use the computer meter. _x005f_x000D_ Built-in watchdog duty circuit, automatic detection of equipment operating status, automatic restart failure. _x005f_x000D_ Standard communication voltage, can be connected with the user switch (PABX). _x005f_x000D_ Automatic IP function, multiple IP settings. _x005f_x000D_ Fixed long-distance automatic insertion of the calling IP prefix, such as 17951,17911,193 and so on. _x005f_x000D_ International, domestic, local calls and other types of access settings. _x005f_x000D_ Preset local area number, local segment and forbidden dialing number or segment. _x005f_x000D_ Encryption settings, such as PIN code, PUK code encryption card lock function. _x005f_x000D_ LED lights display information such as signal, standby status, working status, etc. _x005f_x000D_ _x005f_x000D_ Specifications:_x005f_x000D_ Plug: 100-240V US/EU/UK/AU_x005f_x000D_ Color: white_x005f_x000D_ Caller ID: Yes_x005f_x000D_ Interface form: RJ11_x005f_x000D_ Support network: GSM: 1900/1800/900/850M_x005f_x000D_ Visual function: None_x005f_x000D_ Scope of application: wireless access, security_x005f_x000D_ Number storage function: Yes_x005f_x000D_ Recording function: None_x005f_x000D_ Signal sensitivity: