California Code, Vehicle Code - VEH § 375

(a) A headlamp, auxiliary driving, passing, or fog lamp, fog taillamp, taillamp, stoplamp, supplemental stoplamp, license plate lamp, clearance lamp, side marker lamp, signal lamp or device, supplemental signal lamp, deceleration signal device, cornering lamp, running lamp, red, blue, amber, or white warning lamp, flashing red schoolbus lamp, side-mounted turn signal lamp, and schoolbus side lamp.

(b) An operating unit or canceling mechanism for turn signal lamps or for the simultaneous flashing of turn signal lamps as vehicular hazard signals, and an advance stoplamp switch.

(c) A flasher mechanism for turn signals, red schoolbus lamps, warning lamps, the simultaneous flashing of turn signal lamps as vehicular hazard signals, and the headlamp flashing systems for emergency vehicles.

(d) Any equipment regulating the light emitted from a lamp or device or the light sources therein.

(e) A reflector, including reflectors for use on bicycles, and reflectors used for required warning devices.

(f) An illuminating device that emits radiation predominantly in the infrared or ultraviolet regions of the spectrum, whether or not these emissions are visible to the unaided eye.

(g) An illuminated sign installed on a bus that utilizes an electronic display to convey the route designation, route number, run number, public service announcement, or any combination of this information, or an illuminated sign utilized pursuant to Section 25353.1.