LED light units
LED lighting is becoming increasingly more popular on caravans & trailers. They are virtually maintenance-free and are usually very reliable. LED lights are far less susceptible to the damp as many are waterproof.
The voltages can vary as well, many can run with 12v or 24v which makes them ideal if the trailer or caravan were to be towed by a commercial vehicle.
Standard caravan and trailer lights can easily be changed to LED lights as the wiring colours are the same and many of the mounting holes are the same as well.
LED lights are known to be much more reliable than standard bulbs, many trailers vibrate when towed empty which can be enough to shorten the life of a bulb dramatically. Also, the connections to the bulbs can vibrate causing the connections to get warm and fail. Led lights have none of those problems.
Standard light units with bulbs can easily be replaced for either LED caravan lights and LED trailer lights. Many of the mounting screws share the same dimensions so it makes the change over very straightforward.
Waterproof LED trailer lights are ideal for boat trailers. Just being near the coast can accelerate corrosion in standard light units, they must never be submerged. Again, waterproof LED trailer lights don't have any problem with corrosion and can be submerged when launching and retrieving a boat.
The amount of power LED lights require is a lot less so the drain on the vehicle battery is significantly less therefore the lights can be left on for a great deal longer if required
One consideration that should be taken into account before fitting LED rear lights is that some vehicles rely on the current draw from a bulb to recognise that a trailer or caravan is attached to the vehicle. However, many good quality LED light units are designed to draw enough power so the towing vehicle will recognise it. Should the problem occur ballast resistors can be fitted in parallel to overcome the problem.