An illuminated bike horn includes a ring attached to a mouth of the bike horn. The illuminated bike horn further includes a light source and sound sensor coupled between the bike horn and the ring. The light source provides illumination in response to the bike horn emitting sound generated in response to movement of a diaphragm coupled to a bell of the bike horn. The light source is a light emitting diode (LED) configured to provide illumination in a plurality of colors. The LED provides illumination for a predetermined period of time during and after the bike horn emits sound. The light source and sound sensor are powered by batteries. The batteries, light source, and sound sensor are secured to bay of a back side of the ring between the bay and a cover. The illuminated bike horn further includes a clamp to attach the bike horn to a handlebar.

The disclosure relates to an illumination unit, in particular an elongated illumination unit, on the outside of a motor vehicle, comprising a housing having at least one light emission opening which is closed by a light-transmissive cover plate, wherein the housing has two end regions, arranged in which in each case is an illumination assembly having at least one light source that is designed to emit light through the cover plate. In a rear housing wall, i.e., in a rear wall of the housing, between the two end illumination assemblies are arranged at least one air inlet opening and, separate therefrom, at least one air outlet opening, wherein the air inlet opening is connected to the vehicle interior of the motor vehicle, whereas the air outlet opening is connected to an outer area of the motor vehicle. This establishes during operation of the motor vehicle an automatic air circulation in the interior of the housing from the air inlet opening to the air outlet opening that is brought about by a pressure difference between vehicle interior and outer area of the motor vehicle.