Mach Speed Indicator, .3-1 Mach, Aero Commander/IAI Westwind Lily Bomber It covers instruments

It covers instruments

for the US Army Air Corps

The two neon bulb holders are in place

otherwise each page is clean

The housing looks to have been repainted at some point in its history

Mach Speed Indicator, .3-1 Mach, Aero Commander/IAI Westwind Lily Bomber It covers instrumentsThis 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!