Arduino GSM Shield - Original - Integrated Antenna info
Arduino GSM Shield is a board that makes it possible for Arduino boards to connect to internet over GPRS. To connect the internet and create applications that work over the internet all you need to do is to connect your Arduino board to the Arduino GSM Shield and add a SIM card of an operator which provides GPRS service. By using Arduino GSM Shield, you can create applications working on the internet, you can send or receive SMS. With the addition of external microphone and speaker, you can even make voice calls.
Arduino GSM Shield - General Specifications
M10 Quectel Modem
Can create applications working on the internet
Can send/receive SMS
Voice calls with external microphone and speaker addition