Mask, Oxygen, Type MS-22001. Size medium. Developed from the WW2 A-13A, this pressure demand oxygen mask probably dates from the early 1950s and is fitted with a webbing harness and a green plastic exoskeleton. The rubber is generally in very good flexible condition but some trimming to the internal profile has been made. Good harness but some surface corrosion of the metal parts. The oxygen hose is very good and fitted with a USN 83-C-3 connector. Unwired. This would go very well with the USN H-4 or APH-5 helmets currently listed. Stock code O25068.