Rare 1918 model German helmet with ear cut out. The main purpose of the cutout helmet was to provide better hearing in the trenches and to reduce explosive resonance and echo created by the large flared skirt. A correct M18 "cut-out" helmet must bear the maker mark ET 64. The Eisenhutten werk plant at Thale was the only company to receive a contract to produce this helmet. They made this helmet only in shell size 64 and less than 100,000 were produced.