This is Small SIM800L GPRS GSM Module
Micro SIM Card Core Board Quad-band TTL Serial Port with the antenna, in
this module two antennas have been included.
GSM/GPRS module is a miniature GSM modem, which can be integrated into a
great number of IoT projects. You can use this module to accomplish
almost anything a normal cell phone can; SMS text messages, make or
receive phone calls, connecting to the internet through GPRS, TCP/IP,
and more! To top it off, the module supports quad-band GSM/GPRS network,
meaning it works pretty much anywhere in the world
is made of wire (which solders directly to NET pin on PCB) – very
useful in narrow places. Second – PCB antenna – with double-sided tape
and attached pigtail cable with IPX connector. This one has better
performance and allows to put your module inside a metal case – as long
the antenna is outside.
Caution: Use a resistor divider circuit before interfacing it with Arduino to avoid the damage to the module.
TTL serial port for serial port, you can link directly to the micro-controller.
Don’t need MAX232.
Power module automatically boots, homing network.
Onboard signal lights all the way.
It flashes slowly when there is a signal, it flashes quickly when there is no signal.