Tachometer, Air Ministry, Mk IA, 6C/223 (Serial 134/42) C-43 25 inches diameter by 5

25 inches diameter by 5 inches deep

color-tabbed sections:

The operating limits for the aircraft in which it was installed are marked in red & green tape adhered to the outside glass

The pointers are marked L and R

this indicator was being used in late models of medium bomber B-26 Marauder

Tachometer, Air Ministry, Mk IA, 6C/223 (Serial 134/42) C-43 25 inches diameter by 5Here is a WWII era Mk IA chronometric (mechanical) tachometer of the British Royal Air Force, Air Ministry stores reference number 6C 223, serial number 134 42. This tachometer measures from 500 to 5000 RPM, and has a totalizing counter which measures up to the millions of RPM. The "6C" prefix in the stores reference number indicates that this tachometer was intended as a test instrument, and the "42" in the serial number indicates a manufacturing