(a) Siren Markings. Each siren shall be permanently marked with the manufacturer's or vendor's name, initials, or lettered trademark and a model designation in letters and numerals at least 3 mm (0.12 in.) in height.

(b) Component Markings. Each major component of an electronic siren, including the speaker, speaker driver, amplifier, and control panel (if separate from the amplifier), and each mechanical and electromechanical siren shall contain the required markings.

(c) Driver Markings. Speaker drivers for electronic sirens shall be marked to include the rms wattage in addition to the markings required in preceding subsection (a).

(d) Control Markings. Electronic siren controls shall be marked to indicate each siren function by the words “Manual,” “Wail,” and “Yelp” spelled out or abbreviated. Markings for other nonpermitted functions, such as “Hi-Lo,” may remain on the control panel provided the function is made inoperable on sirens manufactured after January 1, 1978.

(e) Permanence of Markings. Required identification markings shall be molded, etched, embossed, stamped, engraved, or printed with epoxy paint or screening ink on the device or on a metal label of substantial thickness permanently affixed to the device by welding or metal fasteners. Speaker driver markings may be of indelible ink or nonepoxy paint when protected by coverings or they may be stamped on a metal plate attached by a screw.

(f) Visibility of Markings. Required siren markings, except those on the speaker driver and on speakers mounted within warning lamp housings, shall be clearly visible when the siren is installed on a vehicle. Amplifier markings may be on the front, top, sides, or bottom of the case provided they are in a location where they are legible to a person inspecting the component without using mirrors or removing the component when it is installed in a vehicle. The markings on devices in vehicles licensed under Section 5001 of the Vehicle Code need not be visible in the installed position.