The GSM Module/GPRS based on the Simcom Arduino Shield module. The module allows you to obtain SMS, MMS, GPRS and Audio via UART commands by sending AT commands (GSM commands 07.07, 07.05 and simCOM enhanced with COM commands). The module also has 12 GPIOs, 2 PWMs and an ADC from the SIM900 module (they are all 2V8 logic) present on board.

Solid State Relay - 8 Channels

In/Out Shield for your Arduino, Velleman.