TheLEDstation LED Rear Cargo Light Kit includes two LED Bulbs that are built with 13 LED chips per bulb.
LED stands for "Light-emitting-diode", it is a semiconductor device with two terminals, typically it only allows current to flow in one direction, therefore they are polarity specific. Unlike incandescent bulbs that are used on most vehicles, LED's do not have a filament that produces both heat and light, instead it has electrons that flow to create photons, which generate very low heat. LED's use much less energy to create an increased amount of brightness compared to incandescent lights, and last longer.
LED are polarity specific, if it does not turn on after install, please reverse the polarity by turning the bulb around.