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Custom And Factory Headlamp Glossary

Today`s custom headlamp assemblies offer a dazzling array of features and benefits. Here, we define a number of descriptive terms you’ll need to know when making a selection.

When searching for a new set of headlamp assemblies for your ride, you may come across any number of terms which require explanation. Like many other accessory categories, headlamps use their own terminology. For your convenience, we provide you with this list, presented in alphabetical order, and with photos to help you identify these features.

Black Headlights (Housing)

"Black headlights" describes a custom headlamp assembly which has a black background, visible through the clear lens. The size and quantity of lighting elements within the assembly determines how much "black" shows. See also "chrome headlights" and "smoke headlights".

CG Black Headlights
Spyder Black Headlights


"CCFL" stands for "Cold Cathode Fluorescent Lighting". CCFLs are used as a type of lighting on halo lights. CCFLs are known for producing a brighter, whiter light compared to non-CCFL halo lights. See also "halos / angel eyes".

Regular Halo Rings
CCFL Halo Rings

Chrome Headlights (Housing)

"Chrome headlights" describes a custom headlamp assembly which has a chrome background, visible through the clear lens. The size and quantity of lighting elements within the assembly determines how much "chrome" shows. See also "black headlights" and "smoke headlights".

Anzo USA Chrome Headlights
Spyder Chrome Headlights

Combined Low / High Beam

A "combined low/high beam" light describes a vehicle which uses ONE bulb per side, with that bulb functioning as both the low beam light AND the high beam light. Such a vehicle will have a total of 2 separate headlight bulbs, one left and one right. See also "separate low/high beam".

Custom Headlamp Assembly

A "custom headlamp assembly" contains design or lighting elements not present in the factory headlamp. The customization could be as simple as color (black background, or smoke tinted lens), or it could refer to advanced lighting elements like halo or LED lights. See also "Factory headlamp assembly".

Chrysler 300 Custom Headlights
LEFT: Chrysler 300 with custom headlamps.
Chrysler 300 Factory Headlights
RIGHT: Chrysler 300 with factory headlamps.


"DRL" stands for Daytime Running Lights. By definition, DRLs are illuminated whenever the vehicle's engine is running. DRLs are therefore "on" during the daytime, and do not light up the road, but they do increase the visibility of the vehicle. Many custom headlamp assemblies feature lighting elements, such as halos or LED strips, which can be wired to function as DRLs. See also "halos / angel eyes" and "LED lights".

Lumen L DRL

Euro Headlights

"Euro headlights" describes a custom headlamp assembly in an aerodynamic shape. The term became popular when the U.S. in the mid-1980s finally allowed the use of custom-shaped assemblies instead of fixed-shape sealed beam lamps. The custom-shaped lamps had been used in Europe for years prior to the change in the U.S.

Mercedes Benz Euro Headlights
LEFT: A Mercedes Benz with Euro headlights.
Mercedes Benz US Sealed Beam Lights
RIGHT: a similar car with U.S. sealed beam lights.

Factory Headlamp Assembly

A "replacement factory headlamp assembly" resembles the vehicle's original headlamp in appearance and fitment. This is the one to choose if replacing a broken unit, and no customization is desired. See also "Custom headlamp assembly".

Chevy Silverado Factory Headlights
LEFT: A Chevy Silverado with factory headlamps.
Chevy Silverado Custom Headlights
RIGHT: A Chevy Silverado with custom headlamps.

Halos / Angel Eyes

"Halo lights", also known as "angel eyes" are a circular ring of light surrounding a round lamp assembly. Halo lights may illuminate with the low beam headlights, or they may function as DRLs, lit any time the vehicle is operating. See also "CCFL".

Spyder Halo Headlights
Spec D Halo Headlights

High Beam

"High beam" headlamps provide a brighter light than low beam, in order to illuminate more of the road ahead. It is designed to be used when no other vehicles or persons who might be disturbed by the light are in front. See also "Low beam".

LED Lights

"LED" stands for "Light Emitting Diode". Compared to conventional lights, LED lights are brighter and longer lasting. In the context of headlamp assemblies, "LED lights" typically are formed into a strip by a row of single LED lights, which serve as DRLs or as a decorative lighting highlight.

Spec D LED Headlights
Anzo USA LED Headlights

Low Beam

A "low beam" headlamp provides forward illumination, limited so as not to be glaring or blinding to vehicles in the lights' path. See also "high beam".

Plank Lights

Set Of Anzo USA Plank Style Headlights

"Plank lights" describes a lighting element within a headlamp assembly with a horizontal element to its surface, so that the light strip resembles a plank of wood.


Plug n Play Headlights

"Plug-n-play" or "plug and play" describes a custom headlamp assembly which is wired with a plug to exactly match a vehicle's factory plug. Electrical Installation of such an assembly is a matter of plugging the lamp plug into the vehicle's plug, with no wire cutting or splicing. Note that some custom headlamp assemblies (as in the photo RIGHT) may have both a "plug-n-play" element (the blue plug) AND separate wires which will require electrical work.

Projector Headlights

"Projector headlights" describes a custom headlamp assembly with the bulb positioned in front of an elliptical-shaped reflector. This reflector reflects the light toward a single focal point in front of the bulb, providing a sharper, more focused beam of light.

Winjet Projector Headlights
Spyder Projector Headlights

Sealed Beam

A "sealed beam" headlamp is a single unit consisting of bulb, lens, and housing. Traditionally made of glass, sealed beam headlights are also of a limited number of fixed shapes, either round or rectangular, each in two sizes only.

Separate Low / High Beam

Sealed Beam
Round (LEFT) and rectangular (RIGHT) sealed beam headlights.

A "separate low/high beam" light describes a vehicle which uses TWO separate bulbs per side, with one bulb serving as the low beam bulb and the other bulb serving as a high beam bulb. Such a vehicle will have a total of 4 separate headlight bulbs. See also "combined low/high beam".

Pontiac Sealed Beams
Separate low/high sealed beam headlights on a Pontiac.
BMW Sealed Beams
On a BMW (RIGHT) within a Euro-style headlamp assembly.

Smoke Headlights (Lens)

"Smoke headlights" describes a custom headlamp assembly which has a smoke tinted lens over a chrome background. The degree of tinting determines in part how visible the chrome background is. In general, the smoke tinted lens will reduce light output. See also "black headlights" and "chrome headlights".

Spyder Smoked Headlights
Anzo USA Smoked Headlights

U-Bar Lights

"U-bar" lights describes a particular kind of LED light accessory within a headlamp assembly. As its name implies, the U-bar light is shaped like a "U". However, its placement within the light assembly may be on its side so that the "U" does not always appear right-side-up.

Anzo USA U Bar Headlights
U-bar light elements may face upward.
Spyder U Bar Headlights
U-bar light elements may face on their side.
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All manufacturer names, symbols, and descriptions, used in our images and text are used solely for identification purposes only. It is neither inferred nor implied that any item sold by is a product authorized by or in any way connected with any vehicle manufacturers displayed on this page.