Detailed Product Description Features: 1) Simple to install and easy to maintain 2) Adopts industrial module to ensure good performance 3) Provides optimized circuit directly connecting the exchange device for extensions 4) Compatible to most telephones, PBX (for office use) and VoIP gateways (for call termination) 5) Strong signals with high gain antenna 6) Attractive plastic casing 7）Support GPRS (optional) 8) SIM card supported (3V, 5V) 9) Caller ID display 10) Provides reversal polarity signal for metering 11) No noise and clear voice 12) Suitable for wide voltage range and low power consumption 13) Suitable for all kinds of weather and environment 14)Support PSTN to GSM;GSM to PSTN; LCR (optional) 15) RJ-11 ports (two extensions: line / phone and line (optional)) 16) Locking PIN / network (optional) Specifications: 1) Air interface standard: GSM 900MHz / 1800MHz/850MHz/1900MHz 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: ≤25mA b) Transmission: ≤400mA 7) Sensitivity: -105dB 8) Dial tone frequency: 450MHz (standard) 9) Surrounding temperature: -10癈 ~ +40癈 10) Relative humidity: 45% ~ 90% (without frost) 11) Atmosphere pressure: 86 ~ 106KPa 12) Environment noise: <60Db 13) Antenna amplifying: 3.5dB (omni directional), 12dB (certain direction / chosen direction) 14) AC power: DC8V - 15V 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): 168 x 110 x 30mm 20) Weight: a) FWT: 250g b) Full set with AC adapter, antenna and box: 600g 21) Colors: black / blue (optional) 22) Connection mode: RJ-11 phone sockets 23) Antenna connection: SMA antenna connection Applications: 1) For public use as payphones 2) For office and home use 3) For rural and mountainous areas 4) For mobile carriages, like ships, automobiles and trains 5) For those places where hardwire-line telephone service is unavailabl