Thatcham Approved: All of our trackers are Thatcham Authorized, Meaning that they are already subject matter to stringent safety testing by Thatcham, to be able to find out their protection and effectiveness. A GPS module communicates frequently with satellites to find out its exact spot, whilst GSM know-how achieves this https://medium.com/@trackerfit11/caravan-trackers-and-why-they-matter-for-theft-protection-dd44f62fcad7