... to 30mA output current for payphone connection 2 SIM cards (SIM 1 + SIM 2), 3 standby channels (GSM A + ... B auto switch, PSTN only, GSM/PSTN auto switch, GSM A only, GSM B only) White backlight LCD for ... calling records Network locking / BTS locking / SIM card PIN locking facility Support extended accumulator battery ... 850/900 MHz), < 1W (1800/1900 MHz) SIM card mode: 3.3 V Antenna impedance: 50 Ohm ...