Stores reference 22c/1396. Manufactured in copper with two female press stud fasteners enabling it to be clipped to the side of the fabric F and G-type helmets. Used in conjunction with the type-H oxygen mask. Also useable on some wartime helmets including the C-type, although not quite the same design as the WW2 variant and technically incorrect. Stamped with reference numbers. Very good used condition. Stock code NIV-o2.