AIRLINE headphones.  These date back to the DC-6, and have been used on the line, then as cockpit spares right up through the modern jet era.  No sane person would choose to wear this head clamp all day, but should the airline issue Minitel (boom mic) fail, this is what you are stuck with.  To be totally correct, your home sim should have a set of these in the seatback pocket.  Excellent condition, guaranteed to work on delivery.