This is a German M35 helmet. When I got it in my possession it had a strange liner. This helmet also has 2 little holes in the front. I have posted a question on the world war helmets forum to find out about this helmet, see: http://www.world-war-helmets.com/forum/index.php?showtopic=6146 These holes are possibly made after the war to install an emblem, it's possible this helmet has been used by a Tsjech fire brigade. The picture below shows the strange liner, trough the same forum I found out this liner is from a Belgium FN49 helmet. This picture shows the ET62 inscription, ET is the manufacturer Eisenhüttenwerke, the factory was located at Thale. 62 = the size of the helmet. The picture above shows this helmet is a M35, the air vent hole is finished with a ring pressed in to it. The picture below shows the liner installed. This is the reproduction liner that didn't fit into the M40.