SIM800L GPRS moodul Micro SIM

Chip: SIM800L

Voltage: 3.7-4.2V

Module size: 2.5x2.3cm

TTL serial port for serial port, you can link directly to the microcontroller. No need MAX232

Power module automatically boot, homing network

Onboard signal lights all the way . It flashes slowly when there is a signal, it flashes quickly when there is  no signal