SIM900 850/900/1800/1900 MHz GPRS/GSM Development Board Modul Kit für Arduino
The GPRS Shield is based on SIM900 module from SIMCOM and compatible with Arduino and its clones. The shield also has the 12 GPIOs, 2 PWMs and an ADC of the SIM900 module(They are all 2V8 logic) present onboard.