Seeed Studio GPRS Arduino Shield V2.1
Hook your Arduino up to GSM/GPRS cell phone network with GPRS shield! You can use your Arduino to dial a phone number or send a text to your friend via easy to use AT commands now. This new version features a quad-band low power consumption GSM/GPRS module SIM900 as well as a compact PCB antenna. Meanwhile, improvements on interfaces and basic circuit have been taken to make it more concise and reliable.