Aircraft Clock, 8-day, Type A-11 PN 21AE

This is a mechanical WWII-era aircraft clock, Type 11 Bulova PN 21AE, that was used across nearly all aircraft of the US Air Corps and Air Force, including bombers B-17, B-24, B-25, and fighters P-38, P-40, P-47, and P-51. It has a serial number prefix of AF-42, so likely made to a 1942 manufacturing order.

The time is set by pulling out and rotating the knob at the front corner and rotating.  The clock winds and runs but we haven't measured its running duration. The internal side of the glass could use cleaning. Measures ~2.25 square and ~1.25 inches deep.