All of the Apollo lunar landing missions were equipped with containers specially designed to isolate small rock or soil samples from possible contamination during transfer from the lunar surface back to the lunar receiving laboratory on Earth. The open end of the can had a knife edge and the lid was fitted with an indium/silver seal, each of which was protected by a Teflon sheet until just before closure by the astronauts. Once filled with a small lunar sample and sealed the contents, including the near vacuum sample of the lunar atmosphere, could be analyzed on Earth to reveal uncontaminated details of chemical composition.
This is an example of the smaller of the two container types. So named Gas Analysis Sample Containers were flown on the Apollo 11 and Apollo 12 missions. Transferred to the Museum in 1974 along with a large number of items used during training, its actual use is not documented.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.