It does not matter whether you have a caravan, boat, car transporter or simply a humble trailer that's used only for trips to the dump - you want to hang on to it.
But sadly, such attachments are easy pickings for thieves. With no immobiliser, alarm or electronic protection, they are vulnerable - and there is a ready market for these tricky-to-trace units once they have been stolen. So if you do not want your caravan to become one of the 3,000 that go missing every year, it is time to fit a hitchlock.
The top products should secure the trailer both on and off the car. So we turned thief for a day, with the help of security expert Giles Verdon, to see which lock put up the best fight.
Our test shows that if you are spending less than £50, you will be wasting your cash. Each of the top three locks cost more than that, and would provide serious protection against all but the most persistent thieves.
The Milenco and SAS were fairly evenly matched, but the former earned our Recommended award by putting up resistance for a few seconds longer. Yet the Bulldog DM Minilock would challenge even a hardened pro, so it's our Best Buy.