These bulbs are a direct replacement for many cars and trucks. In our case, we will be using them on our Freightliner Cascadia Big Truck. Freightliner, in their wisdom, uses this same bulb for low beams, high beams, and fog lights .. so they will be used as replacements for whatever lights fail while on the road running 48 states. Very handy. And the quality and price are great too: 40% more illumination at less than 1/2 of the price at big box stores. My new auto bulb go-to place.