GSM/GPRS shield for Arduino UNO

Modelo: SIM900.
GSM/GPRS shield for Arduino UNO.
The shield GPRS/GSM SIM900 is the easiest way to connect Arduino projects to the cellular network and thus be able to send and receive text messages (SMS), voice calls and even connect to the Internet via GPRS. The Shield SIM900 works in the GSM bands of 850/900/1800/1900MHz. All it takes to add cellular functionality is an active SIM card.
The Shield's main chip is the SIM900: a low-cost, widely supported GSM/GPRS modem. The SIM900 supports AT commands by Serial UART, by using the commands it allows sending and receiving SMS, making calls and connecting to the Internet. In Arduino we can use a software serial port on pins D7 and D8, use the hardware Serial port on pins 0 and 1 or directly use the USB-Serial converter on the Arduino board using pins D0(TX) and D1( RX). The Shield has two jumpers that allow you to select the pins for serial communication.

Specifications:
Main chip: SIM900
External supply voltage: 5-12V DC
I/O Voltage: 5V TTL
Low current consumption: 1.5mA (sleep mode)
Four GSM/GPRS bands: 850,900,1800,1900 MHz
2G cellular technology
GPRS multi-slot class 10/8
GPRS mobile station class B
Compliant to GSM phase 2/2+
Class 4 (2 W @850/ 900 MHz)
Class 1 (1W@1800/1900MHz)
Control via AT commands (GSM 07.07, 07.05 and SIMCOM enhanced AT Commands)
SIM card socket
RTC battery socket
Headphone and microphone miniplug connectors (3.5mm)
SMA antenna connector
Includes GSM antenna with SMA connector
Shield compatible with Arduino Uno and Leonardo
Working temperature: -40°C to +85 °C