Mach Speed Indicator, .3-1 Mach, Aero Commander/IAI Westwind Sperry as set by the pilot

as set by the pilot

and the course knob is a little stiff but turns 360 degrees

This equipment provides a dual range indicator of 0-400 feet and 400-4000 feet

It covers instruments

See photo of a similar antenna mounted to the fuselage of a B-24 bomber

Mach Speed Indicator, .3-1 Mach, Aero Commander/IAI Westwind Sperry as set by the pilotThis 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!