• Quad-Band 850 / 900/ 1800 / 1900 MHz - would work on GSM networks in all countries across the world.
• 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 (1 W @ 1800 / 1900MHz)
• Control via AT commands - Standard Commands: GSM 07.07 & 07.05 | Enhanced Commands: SIMCOM AT Commands.
• Short Message Service - so that you can send small amounts of data over the network (ASCII or raw hexadecimal).
• Embedded TCP/UDP stack - allows you to upload data to a web server.
• RTC supported.
• Selectable serial port.
• Speaker and Headphone jacks
• Low power consumption - 1.5mA(sleep mode)
• Industrial Temperature Range - -40°C to +85 °C

Cautions:

• Make sure your SIM card is unlocked.
• The product is provided as is without an insulating enclosure. Please observe ESD precautions specially in dry (low humidity) weather.
• The factory default setting for the GPRS Shield UART is 19200 bps 8-N-1. (Can be changed using AT commands).
• Power select - select the power supply for GPRS shield(external power or 5v of arduino)
• Power jack - connected to external 4.8~5VDC power supply
• Antenna interface - connected to external antenna
• Serial port select - select either software serial port or hareware serial port to be connected to GPRS Shield
• Hardware Serial - D0/D1 of Arduino
• Software serial - D7/D8 of Arduino
• Status LED - tell whether the power of SIM900 is on
• Net light - tell the status about SIM900 linking to the net
• UART of SIM900 - UART pins breakout of SIM900
• Microphone - to answer the phone call
• Speaker - to answer the phone call
• GPIO,PWM and ADC of SIM900 - GPIO,PWM and ADC pins breakout of SIM900
• Power key - power up and down for SIM900