Mach Speed Indicator, .3-1 Mach, Aero Commander/IAI Westwind Lily Bomber The two neon bulb holders

The two neon bulb holders are in place

This specimen of the Model 2 Sensitive Altimeter is made by Tanaka

each holding 0-60 gals

and is marked "AF USARMY" on its face

for the US Army Air Corps

Mach Speed Indicator, .3-1 Mach, Aero Commander/IAI Westwind Lily Bomber The two neon bulb holdersThis is Mach Speed Indicator, or Machmeter, was made by Kollsman for an Aero Commander aircraft as it is made to an Aero Commander part number, 3883063 1. Likely made for an Israel Aircraft Industries (IAI) Westwind (formerly Aero Commander 1121 Jet Commander). Measures ~3. 25 inches diameter and ~4 inches deep. Can't tell how fast you are traveling relative to the speed of sound without a Machmeter!