Aircraft Clock, Elapsed Time, Elgin, Cold War F9F, FJ-2
This is an original Cold War-era Elapsed Time Clock, made for the Bureau of Aeronautics of the US Navy by Elgin (part number 2137, stock number R88-C-574), as used in aircraft-carrier-based Grumman Cougar F9F-5 and North American Fury FJ2 Jet Fighters. See photo of the cockpit of the F9F-5 from its flight manual dated 1955, showing the location of the clock.
The clock winds and keeps time. The reset mechanism does not reset, so it could use repair. The dial is 1 7/8 inches diameter and is ~1.5 inch deep. The dial and rim show the impact of sun exposure, but the markings are clearly legible.