Compass, Direct Reading Magnetic, Japanese Army Type 98 Kou
This is a WWII-era Direct Reading Magnetic Compass Type 98 "Kou" produced by the Tokyo Aero Indicator Company and used in aircraft of the Japanese Army, such as fighters Type 1 Oscar, Type 2 Nick, Type 3 Tony, Type 4 Frank, and Type 5 Ki-100, according to the Funatsu Aviation Instruments Museum website. See photo of Tony instrument panel showing the location of this compass from a book by WWII Japanese Aircraft researcher Robert Mikesh.
The Kou compass was illuminated by a small lamp located above the glass, which is still installed and intact. Power for the lamp is provided via a connector at the top rear case. The compass could be calibrated using the small N-S and E-W sliders at the top. The small screw to the right of the face labeled "A" is to adjust for error.
The compass is clearly "experienced" but is in remarkable shape given its age and distance from its origin. The fluid is gone, leaving residue inside of the glass. But the compass card is intact and rotating freely. Measures ~ 3.5 inches diameter and ~4.5 inches long.