Hydraulic Pressure Gauge, 20 PSI P-51 This manual covered versions B-36D

This manual covered versions B-36D and reconnaissance versions RB-36D and RB-36E

While "Elgin" cannot be found on the watch or the packaging

The co-pilot would select the tank to view by rotating the knob

Many of these instruments were common in the US Army helicopters used during the Viet Nam War

Here is a WWII-era Sensitive Altimeter Mk XIVA 6A/1703 as used in aircraft of the British Royal Air Force

Hydraulic Pressure Gauge, 20 PSI P-51 This manual covered versions B-36DHere is a aircraft Hydraulic Pressure Gauge, 0 20 PSI, made by Manning, Maxwell, and Moore, part number 6730 03. It is in fair condition. The glass and case are intact. Measures 2. 25 inches diameter and ~2 inches deep.