Altimeter, Sensitive, 35,000 ft, Type KB 31/01 P-61 The Air Force US Army

The Air Force US Army was the predecessor to the US Air Force

The Eugene M

A graduated rotatable ring (verge)

and also contains an anchoring hole for an HF wire antenna support

This example is a US Navy Mark K2

Altimeter, Sensitive, 35,000 ft, Type KB 31/01 P-61 The Air Force US ArmyHere is an Sensitive Altimeter, made by Kelvin Bottomley & Baird aka KBB Instruments, under license from Kollsman, Type KB 31 01. This sensitive altimeter displayed altitude using 3 pointers. The first and longest indicated 100's of feet, and the second indicated 1000's of feet. Ten thousands of feet were indicated by a third and smallest pointer. The knob adjusts the altimeter to the barometric pressure as displayed in the small inset window. It is