Xtreme LED Festoon Bulbs: Xtreme LED festoon ceramic replacement bulbs are designed to be a direct fit for incandescent festoon bulbs. Each bulb features two automotive grade 5500K Philips LumiLED emitters for a pure white output with no unwanted bluish tones. Their high CRI rating also ensures you don't get unnatural greenish tones -- highly unwanted. Thermal Management: The body of the bulb is made entirely out of ceramic to ensure the bulb can withstand higher environment temperatures--way better then lower priced plastic alternatives. We've also taken the pioneering step of mounting the diodes right onto the ceramic body to create the highest possible heat dissipation efficiency -- they're bright and reliable. Dare to Compare: Our ceramic heat sink design ensures that you can't short out the factory map, dome, or cargo light socket; alternate LED festoon bulbs that use aluminum heat sinks can easily fry your socket as aluminum is conductive and can cause a short.