Altimeter, Sensitive, RAF MK XIVA 35K FT
Here is a WWII-era Sensitive Altimeter Mk XIVA 6A/1703 as used in aircraft of the British Royal Air Force, such as in versions of the heavy bomber Lancaster and fighters Spitfire and Beaufighter.
The Sensitive Altimeter displayed altitude up to 35,000 ft using 3 pointers. The first and longest indicated 100's of feet, the second indicated 1000's of feet, along the outer scale, and the third and smallest indicated 10,000's of feet. on the inner scale. The knob is used to adjust the altimeter to the barometric pressure as displayed in the small window at the 6 o'clock position.
The altimeter is in exceptional condition given its age. The glass and case are intact and the markings are precise. Its accuracy is unknown. Measures 3.25 inches diameter and 4 inches deep.