If you need GPRS Module, please purchase EFCom Pro .
GPRS Shield - EFCom is an ultra compact and reliable wireless module. This GPRS Shield is compatible with all boards which have the same form factor (and pinout) as a standard Arduino Board. EFCom is base on SIM900 4 Frequency GPRS module
The GPRS Shield is configured and controlled via its UART using simple AT commands. Just plug this shield on the Arduino/ Freaduino board, you could easy to use AT command control EFCom Shild. You can use the 2 jumper block to connect the SIM900 URAT post to any pins within D0-D3(for Hardware/Software serial port). There is a switch on board , you can use it to select the connection of the UART port or Debug port , even be set on on Arduino, but by the switch and jumper block, the SIM900 can be connect to PC via FT233RL.
The shield allows you to achieve this via any of the three methods:
Short Message Service
We have layout of all of the SIM900' pins to the 2.54 standard pitch. Not just the UART port and debug port be layout. The super capacitor power supply for the RTC. The RTC can work more than 1 days by the power supply of super capacitor. So the SIM900 can keep the time and day when power off.