Assertion: projector's bulb | /r/HasProperty | clocked by the headlamp designer
Facets:
value: to optimize the beam pattern
type: PURPOSE
Source sentences:
text: Transverse-filament bulbs such as the 9004 can only be used with the filaments horizontal, but axial-filament bulbs can be rotated or "clocked" by the headlamp designer to optimize the beam pattern or to effect the traffic-handedness of the low beam.