Altimeter, Sensitive, AN-5728, 35,000 ft, US Navy WWII 209-02, R88-A-300
Here is an early WWII-era Sensitive Altimeter, US Navy AN-5728, made by Kollsman part number 209-02 and FSC number R88-A-300. BU AERO USNAVY is embossed on its face, and has the alternating munsell-green colored markings used across many USN instruments.
This sensitive altimeter displayed altitude using 2 pointers and a small inner dial. The first and longest indicated 100's of feet, and the second indicated 1000's of feet along the outer scale. Ten-thousands of feet were indicated by a small dial below the center axis, which turned to either 10, 20, or 30 at its 6 o'clock position. The knob is used to adjust the altimeter to the barometric pressure as displayed in the small inset window.
It is clearly experienced but in good condition given its age. The glass and case are intact. The knob rotates stiffly. Measures 3.25 inches diameter and ~4 inches deep.