On October 24, 2014, Dr. Alan Eustace used a state-of-the-art Pressure Suit Assembly to ascend to the top of the stratosphere beneath a large, helium-filled plastic balloon and sky dive back to Earth. He reached a maximum altitude of 135,889 feet before parachuting back to Earth, breaking the previous world record. He accomplished this mission by using a pressure suit alone for life support and foregoing the weight of a balloon gondola to ascend to the stratosphere.
In order to establish that the record had been broken, Eustace had to wear independent gauges on his person to record his flight in addition to the tracking that was done from the ground. This is a Larsen and Brusgaard Altitrack altimeter. This altimeter was mounted and strapped to Eustace's forearm for easy reference. While this one resembles commercially available altimeters that the company makes, note the scale on the face. This altimeter records altitudes up to 130,000 feet.
The Eustace-Kwan family donated this item along with the suit to the museum in 2015.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.