Aircraft Gun Sight Type N-6
This is an original authentic illuminated WW2-era Gun Sight Type N-6 as used in flexible gun mounts/turrets of bomber and patrol aircraft of the US Army Air Force and US Navy, such as the B-17, B-24, B-25, and B-26.
This particular sight is oriented for a side-mount to a machine gun. It can be reconfigured by removing the screws to the sight head and reorient it. The sunshade flips up and down as it should. The lamp compartment opens revealing an intact lamp bulb (its ability to illuminate is unknown).
It is in exceptional condition given its age. All of the glass is intact.