Quad-Band 850 / 900/ 1800/1900 MHz-would work on GSM networks in all countries across the world. GPRS multi-slot /8; GPRS mobile station class B. 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 (ASCII or raw hexadecimal). Embedded UDP stack-allows you to upload data to a web server. supported. Selectable serial port. Speaker and Headphone jacks. Low power consumption-1.5mA(sleep mode). Industrial Temperature Range--40 Celsius to +85 Celsius. Application Ideas: M2M (Machine 2 Machine) Applicatoions. Remote control of appliances. Remote Weather station or a Wireless Sensor Network. Vehicle Tracking System with a GPS module. Compliant to GSM phase 2/2+ Class 4 (2 W @ 850/900 MHz) Class 1 (1 W @ 1800 / 1900MHz) 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 8-N-1. (Can be changed using AT commands). Interface Introduction Power select-select the power supply for GPRS shield(external power or 5v of) 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/ of Software serial-D7/D8 of Status LED-tell whether the power of is on Net light-tell the status about linking to the net UART of -UART pins breakout of Microphone-to answer the phone call Speaker-to answer the phone call Colour:As shown Material: PCB Package Contents: 1 x Development Board 1 x Antenna Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.