Electromechanical horn M28

Sound for greater safety: Signal horns are required in vehicles by law so that other road users can be made aware of dangerous situations in a clearly audible manner. With its full sound, the HELLA M28 horn is particularly suitable for commercial vehicles. It is a durable, compact, lightweight horn. Its high sound pressure level generates maximum attention.


The M28 horn is operated by the battery current or a control current coming from the steering wheel. This is passed through a relay to generate a voltage dip-free control current. The control current activates the electromagnet of the signal horn. This in turn attracts a metal core or armature, and above it, the steel diaphragm of the horn. The sound is produced by interrupting the power supply when the diaphragm is tightened and the armature and diaphragm return to the original position.


The HELLA M28 horn is available with a low (340 Hz) and a high (415 Hz) tone and produces a sound pressure level of up to 118 dB(A) at 2 m distance.

Product Advantages

  • Ideal for all types of light commercial vehicles and passenger cars
  • Durable horn with innovative technology
  • Compact size and low weight
  • Wide range horn available in the range
  • Eliminates mechanical wear through electronic design

Technical Data

Diameter 80 mm
Rated voltage

12 V

Sound pressure level at 2 m distance 105 – 118 dB (A)
Frequency range

340 Hz ± 20 Hz (low tone)

415 Hz ± 20 Hz (high tone)

Power consumption

60 W

Current consumption

Max. 3.5 A

Operating temperature -40 °C to +80 °C
Protection class

IP 67

Lifetime 500,000 cycles
Housing material


Type approval

ECE-R28 (lifetime)


Program Overview

Variant Diameter Part number Packaging unit
12 V, 335 Hz ± 20 Hz, low tone, flat connector 80 mm 3AL 007 425-427 32
12 V, 400 Hz, high tone, flat connector 80 mm 3AL 007 425-791 1