The adaptive headlight option is not actually the light bulb, if that's what your referencing. The Adaptive headlight is the option that moves each headlight up to 15 degrees left or right depending on which direction the driver is heading the car. I don't believe there is any difference in the type of headlight bulb that a non-adaptive headlight or adaptive headlight uses. I'm not sure what trim level offers the adaptive headlight option but my xts is the platinum trim and it has the adaptive headlights feature. It's noticable when driving in dark rural areas and dark neighborhoods. I hope this helps.

 

The adaptive headlight feature is for the most part, controlled by two inputs - speed and steering wheel position. Here's the detailed scoop for those who may be interested in how it operates.

CCC

 

Thanks for this PDF about the adaptive headlights! Amazing.