Buy GSM-/GPRS-module SIM800L at the right price @ Electrokit
Simcom SIM800 GSM/ GPRS Module For Communication
SIM800L GSM/GPRS Module
Arduino FM radio (with SIM800) – Cassiopeia Ltd
DAOKI SIM800L GPRS GSM Module MicroSIM Card Core Board Quad-Band TTL Serial Port for Arduino with Antenna 3.7-4.2V with Dupont Cable : Amazon.ca: Electronics