Description The GSM Sim 900A Mini Module is a breakout board that has feature of complete dual band GSM/GPRS module which is specially designed for small market areas for cost effective solutions. It has Quad-Band of 850/ 900/ 1800/ 1900 MHz and Dual-Band of 900/1900 MHZ . It has useful performance for voice, SMS, Data and Fax in a small form factor. Specifications: Name GSM Sim 900A Mini Module Working Voltage Range 4.4 to 5.3V DC Operation Temperature -40°C to +85 °C Working Current Maximum Of 2A, An Average Of 50mA. Working Frequency 900MHz / 1900MHz Sleep Current 4mA Communication Interface TTL Serial Port Interface Logic Voltage 3.3V