yellow and black metal frame

Data is not information: Mengenlehreuhr aka Berlin-clock or as abacus-clock. The first public clock in the world that tells the time by means of illuminated, colored fields, for which it entered the Guinness Book of Records upon its installation on 17 June 1975. By the way: time of photo was 7:39 am :-) How to read the clock: - Add 5 hours per light in uppermost row - Add 1 hour per light in second row - Add 5 minutes per light in third row - Add 1 minute per light in last row - The yellow bubble blinks every second More info: https://en.wikipedia.org/wiki/Mengenlehreuhr