This gprs gsm breakout board is based on the ai-thinker a9g, which is the newest gsm grps quad-band module. you can add voice, text, sms, and data to your project with this module. it is a high-cost performance compared with sim800, sim900. a9 is an ideal solution for m2m applications, suitable for automotive, industrial and pda, personal tracking, electricity environment detection, wireless pos, smart metering, and other m2m applications to provide comprehensive gsm / gprs text messaging, voice and data transmission services.
# working voltage: 5v usb or lipo battery (3.3v-4.2v)
# supports the gsm / gprs four bands, including 850, 900, 1800, and 1900 mhz.
# supports digital audio and analog audio, supports hr, fr, efr, am r voice coding.
# support standard gsm07.07.07.05at command.