ORIGINAL VIETNAM WAR AIRBORNE M1-C PARATROOPER HELMET CHIN CUP
Original US M1 Post war 4-hole web OD7 green chin cup
The first pattern had five holes with zinc eyelets. The post war chin cup had four holes and was OD7 green with "blackened" alloy eyelets.
The 4-hole green chin cups were post 1945 production onwards up to the 1980's.