It's a post war helmet, manufacturer's stamp makes it clear. There should be another stamp with the date of production, but it was cut off. Sadly, it's a common practice among sellers to remove the flap of the liner with this stamp to hide actual date of production and sell it as more expensive WW2 piece. I own two of these, one with date stamp removed and another with manufacturer's stamp missing (probably seller accidentally cut the wrong piece and didn't notice).