The Army Type F-1 Airspeed Indicator was used across a number of US Army Air Corps and Air Force aircraft during WWII, including heavy bombers B-17, B-24, B-29, medium bombers B-25 and B-26, as well as light bomber A-20, according to the Accessories Interchangeability Chart dated Feb 1945. It was also used in versions of US Army Air Force WWII fighters P-38, P-39, P-40, P-47, and P-51.  This F-1 was made by Bendix, part number 142-22B-A-A1, and has a serial number prefix of AF42, indicative of a 1942 manufacturing date. See spec sheet in photos.

According to the spec sheet in the Index of Army Aeronautical equipment Volume 6 Instruments, dated 1944, the Army type F-1 is a sensitive airspeed indicator. The pointer makes one revolution every hundred miles per hour. A smaller inner window rotates and indicates hundreds of miles per hour