Rate of Climb / Vertical Speed Indicator, 6000 ft/min, Type C-2, US Army Air Corps
The Army Type C-2 Rate of Climb /Vertical Speed 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 Corps WWII fighters P-38, P-39, P-40, P-47, and P-51.
This C-2 was made by Bendix, part number 1636-6A-A1, and has a serial number prefix of AC-41, indicative of a 1941 manufacturing date, very early indeed. It is marked on its face: AC US ARMY, for the Air Corps. See spec sheet in photo gallery.
It is in exceptional condition given its age. Measures 3.25 inches diameter and ~5 inches deep.