Italian helmet M33 "four hole" opinions, please.

[Blue Bull]

Hi.

Found this Italian helmet M33, I would like to know more opinions about it.

Thanks.

[Blue Bull]

More pics.

[tankredi]

The frontal hole indicates that this helmet was produced in a lower quality of steel for civic units like fire-police, air protection etc. before and during ww2.
Also the liner made from oil cloth is typical for these civic m33 helmets.

[Ironcrown]

Nice original UNPA (Unione Nazionale Protezione antiaerea) helmet