Features: Based on GSM900MHz/1800MHz SIEMENS TC35i GSM module Support reverse polarity Connect to PBX Support fax Support GPRS Main Functions: Suitable for GSM 850/900/1800/1900MHz, using SIM card Connect with telephones to make and answer calls Support Fax Support GPRS Detect called party answer, and provide exact polarity reversal signal for charging Caller ID Dialer function inside, programmable call routing (such as you can set 193 or 17911 IP phone when launching long distance call) Provide an integrated telephone tone Support redialing and hands-free Available to wireless signal indicator Setting up and modification of parameters through the phone set or PC Double security by phone password and PIN code Technical Parameter Working Frequency: 900/1800Mhz or 850/1900Mhz or 850/900/1800/1900Mhz Phone interface: DTMF line interface(RJ11 Phone Interface) On-hook Voltage: 45V Off-hook current 30mA/41mA Dialing tone frequency: 450Hz Antenna Plus: >3dB Emission Power: 2W Receiving Sensitivity: GSM900: