Detail SIM800C GSM GPRS Module Quad-band Development Board for Raspberry
Basic features : Arduino 51 STM32 AVR MCU and Raspberry compatible GPIO socket
Frequency 850/900/ 1800/1900 MHz Power supply range: voltage is 5V-20V or 3.4-4.2V; current is 1A or more (the current is very important). Operating temperature range: -40 degrees C to +85 C Communication interface: The TTL level serial interface compatible 2.85/3.3/5v MCU LED: Two led, the Net led and the PWR led. Size:44*52mm SIMCARD: micro SIMCARD holder Voltage:5V-18V