M5Stack® Wireless GSM Module SIM800L Stackable IoT Development Board for Arduino ESP32 with MIC & 3.5mm Headphone Jack

Description: SIM800L is a cellular phone module, integrated SIM800L, a GSM/GPRS module, only cpmpatible with 2G network. if you want to integrate a cellular module into your design with vioce, text and SMS, this hand-solderable module is pretty nice. Series Protocol: UART Product Features: 3.5 mm phone audio jack MIC (MIC is disable by default. To enable it, you will need to weld a 0 ohm resistor at MIC-EN ) Supply voltage: 3.8V - 4.2V Recommended supply voltage: 4V Power consumption: sleep mode