Russian Headgear Sizing Question

[brokenforks]

Hello all, this is my first post on this forum.

I have been looking at soviet tank crew helmets on ebay, finally bought one and it turned out to be the wrong size . I had a Russian speaking friend tell me that it was a size 2 which in and of itself tells me nothing. There is a gentleman on ebay who says he has the same helmet that I'm looking for in sizes 3 and 4.

I was wondering if any of you knew what the sizes 1 2 3 and 4 (or 5 if they made them that big) corresponded to in centimeter measurements? I dread ending up with a helmet that is too big for me .

[Dimas]

If your friend understand Russian- that's for him Need info about shoes and uniform, just tell me know