Dual-band 900 1800 MHz or 900 1900 MHz GSM GPRS Modem Internet, Data, SMS, Voice (Optional Fax, TCPIP Services) Remote Control by AT Commands (according to GSM 07.07 and GSM 07.05) Maximum output power 2 W for GSM 900 1W for GSM 1800 or GSM 1900 Input voltage: 5.5 V to 12 V DC Current: 1.8A peak at 5.5 V, 330 mA average at 5.5 V SIM Interface: 3V 5V