... , GSM prefix number can be programmed Auto-prefix of Local area code (programmable) Caller ID display/hiding can be set Support polarity ... 850MHz, GSM 900MHz, GSM 1800MHz (7 kinds) GSM 1900MHz, GSM 850/1900MHz, GSM 900/1800MHz, GSM 900/1900MHz Frequency stability: < 2 ... .5 ppm Receive sensitivity: < -100 dBm Transmit power: < 2W (850/900 MHz), < 1W (1800/1900 MHz) SIM card mode: 3 ...