This is the case for an HP-35 scientific calculator, introduced by the Hewlett-Packard Corporation in 1972. It was designed to fit in a shirt pocket. This specimen was not flown in space. Similar HP-35 calculators, however, were used in the Skylab missions, replacing the slide rules carried on previous Apollo spacecraft. The calculator and case were donated to the museum by the NASA Ames Research Center in Mountain View, California, in 1985.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.