Features: 1) Simple to install and easy to maintain 2) Steady module and reliable design ensures good performance 3) Provides optimized circuit directly connecting the exchange device for extensions 4) Compatible to most telephones, PBX and VoIP gateways (for call termination) 5) Strong signals with high gain antenna 6) Attractive plastic casing 7) SIM card supported (3V, 5V) 8) Caller ID display 9) Provides reversal polarity signal for metering 10) No noise and clear voice 11) Suitable for wide voltage range and low power consumption 12) Suitable for all kinds of weather and environment 13) RJ-11 ports (two extensions: line / phone and line (optional)) 14) Locking PIN / network (optional) Specifications: 1) Air interface standard: GSM 900 / 1,800MHz phase 2+ 2) Frequency ranges: a) GSM 900: i) Transmission: 890 ~ 915MHz ii) Reception: 935 ~ 960MHz b) GSM 1800: i) Transmission: 1,710 ~ 1,785MHz ii) Reception: 1,805 ~ 1,880MHz 3) Channel space: 200kHz 4) User line, bell signal: in line with GB/T15279 5) Max power: 0.25W / 0.5W 6) Consumption: a) Immobility: less than 25mAh b) Transmission: less than 400mAh 7) Sensitivity: -105dB 8) Dial tone frequency: 450MHz (standard) 9) Surrounding temperature: -10°C ~ +40°C 10) Relative humidity: 45% ~ 90% (without frost) 11) Atmosphere pressure: 86 ~ 106KPa 12) Environment noise: 13) Antenna amplifying: 3.5dB (omni directional), 12dB (certain direction / chosen direction) 14) AC power: DC 10V - 20V 15) Input: AC100 - 230V, 50 / 60Hz 16) Output: 12V 1A 17) Switching type / transformer type AC adapter (optional) 18) Connector of power: China 19) Dimensions (L x W x H) (average): 185 x 135 x 22mm 20) Weight: a) FWT: 400g b) Full set with AC adapter, antenna and box: 650g 21) Colors: white / blue (optional) 22) Connection mode: RJ-11 phone sockets 23) Antenna connection: SMA antenna connection Outer packing: Cartons