Ampere (A or Amp)
The unit of measure for electrical current. Basic formula for finding Amp draw (Amps = watts ÷ volts)
A unit of measurement for the luminous intensity of a lamp at a specific spot in the beam.
Dual Filament Bulb
A bulb having two filaments encased in one glass tube. In the case of
halogen headlight bulbs with dual filaments, one filament for the low
beam and one filament for the high beam. The most common dual filament
halogen headlight bulbs are H4, HB2, 9007, and 9004.
High Intensity Discharge
A light source in which light is produced by a stabilized arc that
burns at a much higher color temperature which creates a whiter light
output than a standard halogen bulb. This arc is generated with an
igniting system and ballast.
Color temperature is a unit of measure for the color of light – it is
not necessarily related to the heat of the light source. A higher color
temperature represents a color closer to actual sunlight.
A process in lamp design that molds the lens to control the beam
pattern by deflecting the light to the desired point in the beam. Lens
fluting usually looks like vertical cuts in the lens.
A unit of measurement for the amount of light that a bulb puts out.
Example: common light bulbs emit approximately 170 candela per 10 watts
MSR, A reflector designed to control the beam pattern with a computer
designed surface to project the light precisely to the desired point in
the beam without the use of fluting.
National Highway Traffic Safety Administration, Department of
Transportation, sets the laws and guidelines for the preservation of
safety on public highways.
Society of Automotive Engineers, publishes the recommended practices,
design specifications, and testing procedures for all automotive
The gas used in H.I.D. systems that produce the extreme white color.
Xenon gas is also used in some halogen bulbs to produce a whiter light
and to keep deposits off the glass tube.
A PIAA term used to designate high efficiency bulbs that are designed
to produce greater light output than its rated power consumption.
(Example 55watts = 85watts of light output)