Cabin Altitude and Differential Pressure Indicator, F-89B Scorpion P-51 single-engine electric Tachometer was in

single-engine electric Tachometer was in the 377 series from Kollsman

It is packaged in its original carton

The luminous markings have turned color with age

while introduced during late WWII

but otherwise it is in fine condition for its age

Cabin Altitude and Differential Pressure Indicator, F-89B Scorpion P-51 single-engine electric Tachometer was inThis is a Cabin Altitude and Differential Pressure Indicator as used in USAF's Cold War era Fighter Interceptor F 89 B Scorpion. See photo of the instrument panel from the F 89 B Flight Manual dated 1958, the indicator appears as item 12 on the right side of the panel. The indicator has two pointers one for Cabin pressure altitude, and the other for Outside pressure altitude, each which rotate as the pressures change, the differential pressure being