EU test mark
Vehicle components that have been harmonised and tested on the basis of directives of the European Union are given a special test mark that must be attached to the component in a clearly visible position. In the case of lights, it is usually integrated in the lens or diffusion disc.
The test mark consists of a small e in a rectangle and a number indicating the country of testing. The approval mark indicates that a type approval has been granted and that this vehicle part may be used in road-approved vehicles. In Germany, approval is based on the StVZO (§ 21a).