Directional Gyro, Sperry US Navy Mark IA, AN-5735-1
The WWII-era Directional Gyro Mark 1A was standard equipment in aircraft of the US Navy such as fighters F4F Wildcat, F4U Corsair, and F6F Hellcat. Made by Sperry, part number 646050 to AN-5735-1 spec. The face is embossed with the marking BUR AERO US NAVY (Bureau of Aeronautics).
According to the spec sheet in the Index of Army Aeronautical equipment Volume 6 Instruments, dated 1944, "This unit is equipped with a vacuum-driven gyroscope with its operating range limited to 55 degrees climb, dive, or bank. It is mounted on the instrument panel in the pilot's compartment and connected through a vacuum gage and selector valve to a source of vacuum, either an engine driven air pump or a venturi pump."
It is in very nice condition given its age. The caging knob, while the rubber coating is a bit crinkled, still cages the gyro when pushed in, turns the card when caged, and releases it when pulled out. The copper air intake filter is in place on the bottom. The dial and glass are intact. It appears that the paint of the compass card markings has been updated to non-luminous paint. Measures 4.5 inches square by ~5 inches deep.