Compass, Direct Reading Magnetic, Type B-16 Air Corps US Army in Wood Box
Here is a WWII-era Direct Reading Magnetic Compass Type B-16, which was used across nearly all bomber, fighter, transport, and trainer aircraft of the US Army and US Navy. This compass was typically installed at the top of the windscreen or on the instrument panel, such as seen in B-17's, P-38's, and P-51's.
This example, a B-16 with a 1942 manufacturing year serial number, has been installed by a previous owner into a small wooden enclosure. The compass still contains its damping fluid. The box measures approximately 4 inches square.