This is an original NASA Apollo Command Module (CM) Astronaut Spacecraft Flight Event Attenuator. Would anyone have any idea what it might be or what it would have been used for? (And by anyone I mean Scott!)
It was designed and built by Autonetics, a company who has built some of the most sophisticated electronic equipment for the Government, to "Manned Mission Rated" standards. There are several potted hermetic electronic modules and a series of precious metal (Platinum and Paladium) wire potentiometric variable resistors within this unit.
The Autonetics Inspection sticker dates this device 1965.
There is also an NAA (North American Aviation Corporation) stamp. NAA was the Prime Contractor for the Apollo CM, which was designed to deliver astronauts safely into lunar orbit and to splashdown after reentering Earth's atmosphere in a save environment.
The NAS 9-150 number designates this "Flight Artifact" as part of the Apollo Command Module's critical space hardware and the ME 901-0358-0001 number is a specific designation for it's particular location and use in the Space Capsule.
Aerospace aluminum alloy is used as a structural material. The basic dimensions are about 3.4 inches long by 2.25 inches wide by 0.75 inches thick.