All of your GPS Trackers are pre-set-up by us so that they are working straight away when they arrive. Additionally, GPS tracking devices require SIM cards to relay the real-time location data gathered using GPS satellites. SIM cards are used for sending the information to the users via Web, Mobile app or SMS. The location of the tracker is determined using GPS satellites and sent to our cloud tracking server: GPSLive using GSM services. We supply tracking devices to our customers with a pre-installed and configured Data Roaming SIM Card. This means all you need to do is to either charge your tracker or hard-wire it to your vehicle and it will start reporting it's location right away.