Siemens Wireless Modules. -       Build in 16 GPRS modem in one box -       Sigle power supply for 16 modems -       Power button to control on and off -       USB interface -        Dual Band:  900/1800Mhz Tri Band: 850/1800/1900MHz, or 900/1800/1900Mhz Quad Band EGPRS 850/900/1800/1900 Mhz -       Send MMS -       GPRS class 10:max 85.6kbps(downlink) -       Auto answer function for voice and data collection with the remote device. -       AT command to control and program -       Designed for WAP, MMS, SMS, CSD data, fax, and voice applications -       Support XP/NT/2000/2003/vista operation systems -       Design for high traffic communicaton