Chrome plated sockets
The faces of the sockets are metalized.  This produces a very nice appearance as the sockets are visible through the transluscent taillight lenses.  Also, since this keeps the sockets from turning brown over time due to the high heat of the light bulbs, the fixtures maintain their crisp, clean look throughout the life of the car.

 Proper grommet
The correct grommet is used to keep moisture out of the trunk.  This grommet is specifically designed for this application, just like the OEM harnesses.  It is not an off-the-shelf, ill-fitting piece like the ones used by other harness manufacturers.

 Cable retainer
Sounds simple, but other manufacturers don't include this small but important feature.  The cable retainer holds the harness in place.  This guarantees proper positioning of the harness, and keeps it from rattling/rubbing against the car body.

 OEM connector
And of course, the original equipment connector is used for quick and accurate "Plug-N-Play" installation.  No splicing or other harness modifications are required.