Original Item: Only One Available. As seen in the permanent collection of the Smithsonian National Air and Space Museum which can be found at this link. Similar helmets were officially designated; Helmet, Flying, Protective, Type P-1A, United States Air Force. We actually aspect sure which model P Series helmet this is, but it certainly confirms to many of the aspects.
The P-1 was the first type of hard helmet mass produced for standard issue to the United States Air Force jet crewmen to provide buffeting and crash protection. The original P-1 was introduced in March 1948.
This example shell is in the original white. Size is approximately a large, the internal lining is gone. This set also has the Sierra Quick-Don Pilot Suspension Oxygen Mask, MBU 5/P. Offered in good condition.