Specification Module model: SIM800L (new module, performance exceeds SIM900/M590) Working voltage: 3.7~4.2V (current highest 1A) Support Network: Global Quad Band Network Module size: 2.5cmx2.3cm The serial port is a TTL serial port, which can be directly linked with the MCU. Module power-on automatically starts, automatically finds the network On-board signal indicator (slow signal flashing, no signal flashing) Small size, no GSM module smaller than this module Full machine chip processing, reflow soldering, stable performance. Package List: 1 x SIM800L GPRS Converter Board