Airspeed / Mach Speed Indicator, 80-850 Knots, 0.4-2.5 Mach, F-8 Crusader

This is an Air Speed / Mach Speed Indicator as used in the Viet Nam War-era US Navy Fighter Vought F-8 Crusader.  Made by Bendix, part number 1454-62A-B62-1.  See photo of indicator on the F-8 panel from its flight manual dated Sept 1978.

The indicator displayed airspeed from 80-850 knots, and mach speed from 0.4 to 2.5 mach. Airspeed is displayed from 80-200 knots on the scale from 1-4 o'clock, and then from 80+ knots on the center inner scale window which is revealed as the speed increases. Mach speed is indicated from 0.4-1.4 mach on the scale from 6-12 o'clock, and then 1.4+ mach at 12 o'clock as the scale rotates. The knob, when rotated, adjusted the maximum speed index pointer along the perimeter of the airspeed scale. When pushed in and rotated, the knob adjusts the index pointer for mach speed along the perimeter of the mach speed scale.

It is in fine condition given its age.  The glass is clear and the lettering precise.  Measures 3.25 inches diameter and ~5 inches deep.