Soviet SSH40 Steel Helmet
This style of helmet was used by Soviet forces during WWI. These particular helmets are dated in the 1950's, so they didn't see any action in WWI, but the same style none the less.
The helmets main shell is made from steel with a padded oilskin liner connected with a cotton drawstring to adjust the size. To hold all this in place we find a cotton webbing chin strap, fastened by a slip buckle.
The P-2 printed on the inside of the helmet means medium/large size.