When lit the OEM rear side markers have an unsightly hot spot that looks dreadful. Installing a set of Smoked Side Markers will replace that ugly hot spot with a bright red, razor sharp LED strip for bold custom styling. A set of Smoked LED Side Marker Lights are a great way to upgrade the exterior appearance of your S550 Mustang. LED Side Markers are made in the USA and use powerful SMD LED focal strips to produce a bright laser-like light. The LEDs feature embedded transient voltage suppression and a constant-current driver to provide excellent, long lasting reliability. The smoked optical reflector looks identical to the original factory part and is ultrasonically welded together to prevent moisture from entering the housing. Installation of these LED Side Markers is 100% plug-and-play. There is no cutting, splicing or resistors required. Just pop out your factory side markers and disconnect the wiring harness. Plug the harness into the back of the LED Side Markers and snap them in place of the old ones. It's that easy!