The R800C GSM/GPRS HAT is a handy, low power for HAT which features multi-communication functionalities: GSM, GPRS, and phone call, applicable to countries or regions with 2G network coverage, up to 85.6kbps GPRS speed. It allows your Pi to easily make a telephone call, send messages, connect to wireless Internet, and so on. Supports SMS, phone call, GPRS, IP, DTMF, HTTP, FTPl, etc ART interface, for connecting controller boards like for /STM32 Onboard voltage translator, 3.3V by default, switch to 5V via jumper Control via AT commands (3GPP 27.007, 27.005, and SIMCOM enhanced AT Commands) Power supply:5V Logic level:5V/3.3V (default) Operating temperature:-40℃-85℃ Storage temperature:-45℃-90℃ Color:As Shown Material:PCB Package Contents: 1 * 2G R800C GSM GPRS Expansion Board Only the above package content, other products are not included. Note: Light reflection 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.