This is a Czechoslovakian Model 1928/1930 steel helmet adopted by a fire department after these helmets were discontinued by the Czechoslovakian Army.1  It is painted black with a chrome ventilation comb.  The front features a brass badge with the Czechoslovakian lion crest superimposed over a fire axe surrounded by a leaf motif.

Czechoslovakia Interwar Period
Civil Helmet
CZH-25-0310

Description by Brian McInturf