Operation thanks to AT commands allows even beginners to operate the device, which enables making voice calls, sending SMS and data transmission. The module is compatible with with Arduino and Raspberry Pi. The kit includes an antenna. Technical data: Chip: SIM900A (version A supports only Asian networks, in order to adapt to European telecommunication networks it is necessary to change the firmware of the system.) GSM network frequencies: 850/900/1800/1900 MHz Supply voltage: 4V - 5.2V Interface: UART TTL Interface: RS232 Communication using AT commands Standard SIM card connector LEDs indicating the operation of the module 2dBi antenna included Dimensions: 50mm x 48mm https://elecena.pl/product/22624859/sim900a-gsm-gprs-wireless-extension-module-antenna 2023-02-23 https://elecena.pl/product/22624859/sim900a-gsm-gprs-wireless-extension-module-antenna 2025-03-11 https://elecena.pl/product/22624859/sim900a-gsm-gprs-wireless-extension-module-antenna 2025-10-26 https://elecena.pl/product/22624859/sim900a-gsm-gprs-wireless-extension-module-antenna 2025-10-28