Piaa 880 Xtreme White Plus 27w = 50w XTRA, 4000K Pair. PIAA’s Xtreme White Plus 880 bulb with a Kelvin rating of 4000K provides an intense white light with the superior performance of XTRA Technology. So lose those boring factory fog light bulbs and upgrade to PIAA’s Xtreme White Plus 880 bulb and experience the difference. #18880