After World War II, the Viet Minh
based their helmet design on the French pith helmet of the former colonial power and adopted it as their own. Today it is still widely worn by civilians in Vietnam (mostly in the North, but its use has seen sharp decline since 2007 when the motorbike helmet became mandatory for motorbike riders) but appears only rarely as part of the military uniform. In design, the Vietnamese model was similar to the pre–World War II
civilian type, but covered in jungle green cloth, sometimes with a metal insignia at the front.
(based on Wikipaedia: en.wikipedia.org/wiki/Pith_helmet