It can be used as a straight bulb replacement but i used a wiring harnes with relay to make it work properly. It is much more brighter than normal halogen. I have 6000K bulb in it.manalagi001 said:Good question. Is it just a straight bulb replacement or is there more to it? What are the benefits? If it's brighter, can it be too bright? Or too blue? I hate those cars with blue headlights, makes them look like they are not headlights at all. Confusing when on the road at night.