This neck dam was worn by astronaut Alan B. Shepard, Jr., Commander of the Apollo 14 mission that occured in January 1971. The neck dam sealed the spacesuit at the neck to provide extra flotation and greater in-water comfort/ thermal protection in a rescue emergency.
NASA transferred this neck dam to the museum after the Apollo 14 mission.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.