Astro Compass, Mk II, and Case, Sperti
A WWII-era Astro Compass, Mk II, in its original bakelite case, used for celestial navigation. Used across many versions of US Army Air Force aircraft with navigator crew during the era, such as bombers B-17 Flying Fortress, B-24 Liberator, and B-29 Superfortress, and transports C-46 Commando, C-47 Dakota, and C-54 Skymaster. The compass would be placed in a fixed mount on top of the instrument panel or in the navigators compartment, and sighted to a known star, e.g. North Star. The bearing of the aircraft can then be determined by using/aligning the indexing scales on the components of the Astro Compass.
It is in very good condition for its age. The only issue is the plastic Delineation label on the top of the sight, which appears to have deformed from heat or sunlight. The bubbles in the levels are intact and all other mechanical functions appear to operate as intended.
Here is a helpful video on the Astro Compass from a fellow enthusiast.