This is a WWII-era Gyro Horizon Indicator as used in aircraft of the Japanese Army. It appears to be either a Type 98 or 100. The date on the label is Showa 11, which is 1936. The knob at the lower left adjusts the flow of air through the pneumatic connection to the gyro inside. The gyro horizon moves freely within its housing.
Why we like it
This is a really pristine example of an analog gauge from the early 20th Century – It’s a simple and beautiful depiction of essential information for the pilot. The facing of aircraft and scale on top with the gyroscope moving freely underneath condenses the information in an effective way. It’s very easy to imagine a digital version of this in modern day aircraft.