12n type Plug are used for road lighting only.

This is currently the most popular Plug used for towing as it does the lighting on most trailers and caravans.
All trailer plugs and sockets are very simple to wire.

All pins are marked and it can only be assembled one way.

Easy to wire as follows;
PIN 1 - Yellow Wire (Left Indicator)
PIN 2 - Blue Wire (Fog Lamp)
PIN 3 - White Wire (Earth Return)
PIN 4 - Green Wire (Right Indicator)
PIN 5 - Brown Wire (Right Side light)
PIN 6 - Red Wire (Brake lights)
PIN 7 - Black Wire (Left Side light)