GSM/GPRS shield for Arduino UNO

Model: SIM800C.
GSM/GPRS module for Arduino UNO.
Description:
SIM800C is a four frequency GSM/GPRS module, for Arduino UNO. It's working frequency is 850/900/1800/1900MHz GSM/GPRS, it can achieve low power transmission of voice, SMS and data information. SIM800C size is 17.6 *2.3 *15.7 mm.

Specifications:
The power supply interface supports the 5-26V voltage input. When the voltage is 5-9V, the power supply adapter current must provide no less than 2A.
Communication interface for TTL level serial port. Fully compatible with for Arduino, and compatible with other 5V, 3.3V, 2.85V systems.
Supports four frequencies 850/900/1800/1900MHz
Suports short message (SMS)
Supports FTP/HTTP, embedded TCP/UDP protocol
Supports DTMF detection, Bluetooth 3.0 (optional), USB interface.
Use the hardware serial port (D1 D0) or software serial port (D8 D7) can be set by jumpers.
Support update SIM800C firmware via USB or serial port.
Support micro SIM cards.
Supports four segments headphone jack.