Main Functions: 1. Suitable for GSM 900/1800 MHz, using SIM card 2. Can making calls via GSM or PSTN by hand. 3. Big LCD display which can show signal intensity, clock, battery consumption, new message, startups of alarm and so on 4. Caller ID 5. Language available: English, Chinese 6. Support SMS, Call log, phonebook, call service and so on. 7. Support the functions of redialing and hands free. 8. Built-in PIN code protection featured with locking device/card/network 9. The power supply adopts both battery supported and external adapter. Technique Parameters: Working Frequency: GSM900/DCS 1800/PCS 1900 Emission Power: (2W) 900MHz/ (1W) 1800MHz Channel Interval: 200 KHz Working Voltage: 5V Environment Temperature: -20ò¾ ~55ò¾ Working Humidity: 45% ~95% Atmospheric Pressure: 86~106Kpa.