Ammeter, DC, Dual Engine, Weston 827 Type 28Y1, C-121 Lockheed Constellation
This is a dual DC Ammeter, 0-450 amps, as used in the US Air Force C-121 transport version of the Lockheed Constellation. See photo of the location of the instrument on the MJB-1 control panel from the C-121 flight manual dated 1958. This instrument has a date stamp of 1957. Measures 3.25 inches diameter and 3 inches deep.