Light Emmiting Diode (LED) is a semiconductor device that emits incoherent narrow-spectrum light when electrically biased in the forward direction of the p-n junction. This effect is a form of electroluminescence.
LEAD (IPA: /lɛd/) is a chemical element in the periodic table that has the symbol Pb (Latin: plumbum) and atomic number 82. A soft, heavy, toxic and malleable poor metal, lead is bluish white when freshly cut but tarnishes to dull gray when exposed to air.
Just kidding though And Yes 2006-2007 LED tails will fit on 2004. It's just plug-n-play installation.