The German Federal Environment Agency (Umweltbundesamt, UBA) as funding body, the Leibniz Institute for Tropospheric Research Leipzig (TROPOS) as project coordinator, and all other participants of the project ULTRAFLEB therefore organised a final workshop on 14 May 2025 at the Bundespresseamt (German Federal Press Office) in Berlin (online participation was also be possible. The event was held in German). The event was of a scientific nature and was aimed at a specialist audience, in particular scientific institutes and authorities related to air quality measurements