Above the windows on the first floor are letters made of white tubes and three rings each in the colors blue, red and yellow. This combination of lettering and rings runs around pretty much the entire facade of the round-arched corner building on the corner of Karlstrasse and Mathystrasse. Towards Karlstrasse there is another vertical cantilever made of white, yellow, red and blue tubes.
The device was built by the Büttner company in 1955 and, like the Ringcafé, was painted and the elements regenerated every now and then.
Many thanks to Mr. Michael Brenner for the further information!