Features:
· Chip: SIM800L
· Voltage: 3.7 - 4.2V
· Support networks: Global Quad-band network
· Module size: 2.5 x 2.3cm
· 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