Features: 1) Locking onto a specified GSM carrier and service area is programmable 2) Support SIM card locking (terminal refuses to take any other SIM card except the one set to be accepted) 3) Designed for low power consumption and support Li-ion battery and external DC adapter 4) Powerful encryption to ensure high security of data 5) Capable to retain operational parameters and data upon power breakdown 6) Provided with super password to access engineering mode for senior configuration 7) Support downloading parameter setting on the configuration program with a data cable 8) Support PC fax and GPRS data function 9) Can be connected to PBX (PABX) for office use or VoIP gateways for call terminations 10) Charge with charge meter for payphone use 11) Polarity reversal signal Technical specifications: 1) GSM module wavecom 2) Four band GSM 850/900/1800/1900MHz 3) Signal receiving sensibility better than-105dBm 4) Power output max: 33 ± 2dBm 5) Min: 5 ± 5dBm max: 30 ± 2dBm 6) Min: 0 ± 5dBm Environmental 1) Temperature - 10 °C to + 60 °C 2) Relative humidity 0% to 95% 3) Noise 3 hours 6) Quoted standby time > 15 hours Structural dimensions: 180mm x 122mm x 32mm