Original U.S. Vietnam War USN USMC Pilot APH-6 Dual Ramshorn Flight Helmet with Oxygen Mask Ammunition and it shows it

and it shows it

It has a dim yellowish luster

Issue 2 article ‘White City

We are not sure what this symbol means

Leaflet is totally original and measures 8" x 5 3/4"

Original U.S. Vietnam War USN USMC Pilot APH-6 Dual Ramshorn Flight Helmet with Oxygen Mask Ammunition and it shows itOriginal Item: Only One Available. At the end of the 50's the APH series helmets introduced a new generation of flight helmets characterized by the external visor covered with a protective shield. Improvement of the communication system, internal liner and oxygen mask retainers was also made and in some versions the dual dark and transparent visors system was installed. These types of helmets were the US Navy and USMC standard jet aircraft headgear