The GPRS (General Packet Radio Service) Shield provides GSM/GPRS 850/900/1800/1900MHz communications for voice, SMS, data, and fax. It is controlled via AT commands (GSM 07.07 ,07.05 and SIMCOM enhanced AT Commands). The GPRS Shield has 12 GPIOs 2 PWMs and 1 ADC(They are all 2V8 logic).

Features:
Quad-Band 850/ 900/ 1800/ 1900 MHz
GPRS multi-slot class 10/8
GPRS mobile station class B
Compliant to GSM phase 2/2+
Class 4 (2 W @850/ 900 MHz)
Class 1 (1 W @ 1800/1900MHz)
Control via AT commands (GSM 07.07 ,07.05 and SIMCOM enhanced AT Commands)
Supply voltage range : 3.1 … 4.8V
Low power consumption: 1.5mA(sleep mode)
Operation temperature: -40C to +85C

Arduino Seeed Studio GPRS Shield Pinouts