Classical HAC chess clock, produced in Germany between ca 1910xx and 1930xx. This model was also retailed by other known manufacturers (like Jacques). It is noticeable, tha early soviet clocks were plagiarized prototyped out of this model (except for clock movement, which has been surely stolen prototyped from somewhere else ;) ). Particularly this clock belonged to the German chess club Kleeblatt Fürth (1950-1966). Photo: M.Euwe vs M.Botwinnik, International Chess Tournament (Groningen, 1946).

Another HAC model, this time retailed in Netherlands. A metal shield on the back side refers to the Company "WJ Van den Berg", assumable an Amsterdam watch reseller, operated (according to this reference) in 1920xx.