This is a North Vietnamese Army Cap Badge. The predecessor to this badge was the simple five pointed star badge worn by the Viet Minh. Following the defeat of the French the NVA standardized their headgear insignia with this badge. This badge was pinned to the front of the helmet or to whatever cloth cap was issued at the time. Most wartime photographs show this on helmets. NVA badge with a cog at the bottom, rice stalks on the side and a star with sunburst behind it. Regardless, this badge was worn well into the late 1960s as seen in photos and on captured headgear.