Hi, a couple of weeks ago a friend of mine had his caravan stolen from the compound where he stores it, he had a Tracker fitted which he had activated at around 5pm and the van was found by 10am the next morning, a couple of facts for you, there are many tracking systems/devices on the market there is actually only one thats called Tracker, the rest will be call by a name followed by the words tracking system or location system such as the Hal Locate, the system which is Tracker is also the only tracking system which is operated by every police force in the uk, all others either rely on GPS to locate where the van is or some use a system of radio masts around the country to pick up the signals from the unit fitted, GPS is great when the unit is able to see the required satellites to get a fix but put the van in a metal building such as a barn and the signal becomes either weakened or none existent, at the end of the day you pay your money you take your pick, for me the fact that the police operate the actual tracking in the case of Tracker speaks volumes, best of luck with your choice and fingers crossed whichever way you go you will never have to use the Tracking system. Beehpee