This device is GREAT ! In my experience, this device will only work with a T-Mobile "Prepaid" SIM card, or a BlackVue SIM card in North America. I am unaware if an AT&T SIM card will work with this device. Save yourself some trouble and do your research to see which SIM cards will work with your device, depending upon your location. I followed the cloud connection steps in the BV App, which told me that my setup was complete. However, if the cloud icon does not turn blue in the BV app next to the camera name, then your camera is not connected to the cloud. My only option was to use the BlackVue Sim card and connect to the BlackVue cloud. The front camera is larger than I expected. Installation is pretty straightforward. I opted to install the BlackVue battery pack under the drivers seat. Search YouTube for installation guides for your specific vehicle. You may need to remove the vehicle camera shroud behind the rearview mirror in order to fish the wires behind the front headliner. The cameras work very well. I had to adjust the settings in order to obtain optimal performance. BBMC stands behind their products. Troubleshoot with them first if you have a problem, then contact BlackVue Warranty returns are pretty easy. Be sure to ask for a return label if shipping to Canada. You will have to pay for the return label which includes customs forms. This may have changed recently, so be sure to check with BBMC before you return anything. They have recently added US return locations, so you don't have the hassle of requesting a label from BBMC and dealing with U.S. Customs.