Suction Gage, AN 5771-5, US Army Air Force WWII Luftwaffe and D (Dull) are displayed

and D (Dull) are displayed on the inner ring

The counter-drum-pointer altimeter consists of a pressure altimeter combined with an powered servo mechanism

VBC (Vertical)

with the small "V" pointed toward the front of the airplane

made by Elgin to Air Corps US Army spec #94-27749

Suction Gage, AN 5771-5, US Army Air Force WWII Luftwaffe and D (Dull) are displayedThis is a fine example of an WWII era Suction Gage, AN 5771 5, made by US Gauge, part number AW 1 7 8 21 AK. This indicator has a serial number prefix "AF 43", evidence of a manufacturing year 1943. The AN 5771 5 Suction Gage was used across all aircraft of the US Army Air Corps, including bombers B 17, B 24, B 25, fighters P 38, P 40, P 47, P 51, and transport C 47. The Suction Gage measured the amount of vacuum generated to power the pneumatically