The HPW 11 Signaling Hooter is a sounder used for warning and calling purposes. Its robust housing allows for applications in dry and damp rooms and even outdoors. The model equipped with a telephone call relay is suitable as an additional, high-volume acoustic device for telephones.

The device is driven by a powerful, non-polarized electromagnet with an adjustable tappet that hits the membrane 100 to 120 times per second.

The signaling hooter housing is made of impact-resistant thermoplastic.

The hooter is supplied over a M20 self-sealing grommet for line diameters of 8-12 mm; the hooter with call tone relay comprises two of these grommets.