By the American Optical Co. Green 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. The facepiece is a little distorted but remains perfectly flexible and strap has lost elasticity but the goggles are generally in very good used condition. Stock code G20168.