Many modern vehicles and cars with factory fitted tow bars use the new European 13 N pin plug       

This adapter is specifically designed to easily convert this new 13 pin plug back to the standard 7 pin plug on your existing trailer or caravan.

There is no need to call an Auto Electrician - Simply plug in your 13 pin tow bar plug into one side and your 7 pin trailer plug into the other side and that's it!
It's simple to do and will take you no time at all.