Tri-fold passenger map, 15.5 x 22.8 cm, printed in colours, only trivial signs of use. On the reverse is an enlargement of the central area with interchange stations named inside large diamonds.
Beck’s diagram is possibly one of the most innovative and influential designs of the twentieth century. First published in 1933, Beck remained directly associated with it until 1960 except for a short period when responsibility for revising and updating the map passed to Hans Schleger.