'Mask, Field, Chamois' by Foster Bros. Sportswear Co. Basic single layer, unlined facemask with simple headstraps and cutouts for eyes and mouth. Designed to help prevent the oxygen mask and goggles from freezing to the face at altitude. This example has not been issued and hasn't had the eye cut-outs removed. Storage soiling and age with some corrosion to the metal strap components. Remains supple. Produced in limited numbers as they proved unpopular due to freezing of the moisture soaked mask itself. Stock code H18475.