USAAF WW2 Airgunner Goggle in Case

In a very good, near mint conditon a US Army Airforce Goggle Variable Denisty in it's original case.
The set is made by the American Optical Company. A Black rubber facemask with a rigid plastic frame at the front housing circular lenses.
Each lens is actually comprised of two separate Polaroid lenses, one of which can be rotated over the other using a centrally mounted knob.
The effect of this rotation was to achieve differing degrees of density from clear through a range of pinks/reds and enabled the wearer to track targets in the vicinity of and across the face of the sun.
Used primarily by airgunners.
A very stunning set!

Code: 66264