It consists of a reflector, a light distribution mirror, a light bulb (or LED), a light shield, a vertical light adjustment device, and a casing. The main types are movable devices with replaceable light bulbs and movable reflectors. Most light bulbs are 55W halogen bulbs. In addition, beam adjustment is generally only in the up and down direction.To suppress the phenomenon of light film with unclear field of view caused by diffuse reflection of water and dust particles floating in the air, it is most important to block visible light in the vertical direction. In addition, to expand the horizontal diffusion angle, uniform light distribution is required. The color of the light is white or light yellow.

In addition to the front high beam, low beam, headlights, and small lights, a typical car also has a set of anti fog lights in inconspicuous places at the back of the car, including the driving lights and brake lights. Rear fog lights for vehicles refer to red signal lights installed at the rear of vehicles in low visibility environments such as fog, rain, or dust, with a higher luminous intensity than taillights, to make it easier for other road traffic participants behind the vehicle to detect.

The filament of the light source is designed at the focal point of the parabolic surface of the reflector, and after reflection by the reflector, a beam parallel to the optical axis is formed and emitted. The light distribution mirror diffuses and refracts the light beam to form a wider horizontal beam, and makes its light shape and illuminance meet regulatory requirements. The light shield inside the front fog lamp is designed to block the light emitted by the filament towards the upper part of the reflector, creating a clear cut-off line for light distribution, that is, dark at the top and bright at the bottom. Try to keep the visible area in the upper part of the light distribution shape as dark as possible, while the horizontal diffusion angle on both sides of the lower bright area should be 50 °, forming a horizontal bright area to meet the requirements of not dazzling but providing good lighting conditions for safe driving.