Turn and Bank Indicator Type A-11, AN5820-1 Air Force US Army, WWII, B-17, P-51, P-38
This Turn & Bank Indicator Army Type A-11, AN5820-1, made by Bendix Part No. 1721-2U-A2, was used across virtually all aircraft of the US Army Air Force during WWII, including bombers B-17, B-24, B-25, B-26, fighters, P-38, P-39, P-40, P-47, P-51, and transports C-46 and C-47. Imprinted on the face, but barely discernible in the photos, is "AF US Army", and its serial number prefix is AC-42, indicates the manufacturing year 1942. This unit has the filter for cleaning vacuum air as it is pulled across the gyro to power it.
It is in exceptional condition given its age. The dial markings are clear and the glass and case are intact. Measures 3.25 inches diameter and ~5 inches deep.