Flap Position Indicator Boeing B-17F/G PN 5911-12 USN PB-1
This is a Flap Position Indicator as used in the US Army Air Force Flying Fortress B-17F & G models. The part number has been confirmed in the B-17F Erection and Maintenance Manual dated 1942 and the G model dated 1944. See photo of the indicator on the B-17 instrument panel. Measures 3.25 in diameter and ~4in deep. This indicator is stamped with the US Navy anchor symbol, perhaps evidence of its use in the US Navy's version of the B-17, the PB-1.
The dial markings are clear and the glass and case are intact. See photos.