Amazon.com: OSTENT GSM/GPRS Dual-Band 900/1800MHz 2G Modem with Siemens MC52I Module USB Port Interface at Commands Bulk SMS MMS TCP/IP : Electronics
Amazon.com: Teyleten Robot SIM800C USB GSM GPRS Wireless Module Quad-Band, 850/900/1800/1900MHz, CH340T USB Chip Support 2G 3G 4G SIM Card USB Communication SMS Data Transmission with Antenna (SIM800C is New) : Electronics
GSM/GPRS & GPS modem with SIM900/SIM908 module - Open Electronics - Open Electronics
GSM / GPRS Modems and Routers | ICP DAS USA Inc - Data Acquisition
GSM / GPRS expansion module | Industruino
GSM GPRS Modem, for Location Tracking, Feature : Easy To Use, Fast Working, Light Weight, Speedy at Rs 1,750 / Piece in Mumbai
GSM/GPRS Module
Amazon.com: Module,Development Board Module Kit,5~26V SIM Development Module,Fit for SIM900 850/900/1800/1900 MHz GPRS/GSM,Quad-Band 850/900/ 1800/1900 MHz - Would Work on GSM Networks : Electronics