Pouches and containers like this one were necessary items for storing equipment for spaceflight. This round pouch held a prism lens for a camers.
During launch, equipment such as cameras, lenses, and other experiments could not be loose inside the spacecraft as they could break or fly around and injure the astronauts. To prevent this, they were packaged inside containers and carefully stowed. When not in use during the mission, they were secured with lanyards, Velcro, or in containers to stay out of the way of astronauts as they worked in the small space of the cabin.
NASA transferred this object through the McDonnell Aircraft Corporation to the Museum in 1967.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.