Universal wiring is usually cheaper but it requires splicing into cars wiring which can invalidate car’s warranty. Dedicated wiring often use pre existing connectors and might need coding. We strongly advice to use dedicated wiring for all vehicles past 2010.

7 pins are commonly used for basic lights in small trailers but older caravan eg. Before 2010 use 2 x 7 pins plugs. One for lights and second for powering and charging leisure battery or fridge cooling. Modern caravans have it all integrated in one 13 pins socket.