lightweight lens for a distortion-free image with edge-to-edge sharpness.Lens clamp made from glass fibre reinforced plastic.When not in use the shield can be simply lifted up out of the way.Headband has

lightweight lens for a distortion-free image with edge-to-edge sharpness.Lens clamp made from glass fibre reinforced plastic.When not in use the shield can be simply lifted up out of the way.Headband has