A special assembly, which is found at every crew seat within the flight deck. These are emergency oxygen supply masks manufactured by EROS. The unit is in brown colour and in very good condition.
The unit includes a full EROS oxygen mask unit within the housing, and therefore is a ready addition to your simulator.
This has not been tested in any way, and is intended for simulator use only. In reality, it has flown around the world many times. Purchase a rare piece of aviation history.