East German M56 Helmets. Talk about one of the most iconic cold war helmet. Made and used by the DDR from 1956-1991. There are a handful of different versions, helmet covers and even some with decals. 

Models. 

M56 Original Liners- Made from 56-62 and has the original liners. Very hard to find.

M56/62 - Helmets from 56-71, If made before 1962 but with the improved liner then the liner was replaced. Fairly common.

M56/72 - Helmets from 72 and on. Does not have exterior rivets. Most common helmet type, may be unissied.

Each variant is a different helmet based on model, date, size and condition. 

Listing #1: M56/72 with good liner and slight blemished across helmet. Dated 07/1971 and size 2.