Seeed gprs shield with antenna and external sim holder v3 0 seeed studio 113030009 p the gprs shield from seeed studio is an arduino shield with quad band support for the 850 900 1800 1900mhz bands and tcp udp protocols the shield has a sim socket and is supplied with an external antenna fit your sim into the socket and your arduino is ready to send and receive texts a library is available on github to simplify the process p p seeed provide technical documentation example projects and