Now the car led light is very hot because of energy saving,long life span,friendly environment And as a important part front fog lamps provide a wide, bar-shaped beam of light with a sharp cutoff at the top, and are generally aimed and mounted low They may be either white or selective yellow. They are intended for use at low speed to increase the illumination directed towards the road surface and verges in conditions of poor visibility due to rain,fog,dust or snow As such, they are often most effectively used in place of dipped-beam headlamps, reducing the glareback from fog or falling snow, although the legality varies by jurisdiction of using front fog lamps without low beam headlamps.
 
Use of the car led bulb when visibility is not seriously reduced is often prohibited (for example in the  United kingdom), as they can cause increased glare to other drivers, particularly in wet pavement conditions, as well as harming the driver's own vision due to excessive foreground illumination.The respective purposescar led bulb of front fog lamps and driving lamps are often confused, due in part to the misconception that fog lamps are necessarily selective yellow , while any auxiliary lamp that makes  white light is a driving lamp. Automakers and aftermarket parts and accessories suppliers frequently refer interchangeably to “car led light of log lamp" and "car led bulb of driving lamps" (or "fog/driving lamps"). In most countries, weather conditions rarely necessitate the use of fog lamps, and there is no legal requirement for them, so their primary purpose is frequently cosmetic. They are often available as optional extras or only on higher trim levels of many cars. Studies have shown that in North America more people inappropriately use their fog lamps in dry weather than use them properly in poor weather.