The Apollo Lunar Sample Return Container (ALSRC) was an aluminum box with a triple seal. It was used on Apollo lunar landing missions to preserve a lunar-like vacuum around the samples and protect them from the shock environment of the earth return flight. An aluminum mesh liner helped absorb the shock impacts. Prior to flight, each box was loaded with sample container bags and other sample containment devices. The "rock box" was then closed under vacuum so that it would not contain pressure greater than the lunar ambient pressure. On the moon, while samples were being loaded, the seals were protected by a Teflon film and a cloth cover which were removed just prior to closing the box. Two ALSRC's were used on each mission.
This particular ALSRC was used on Apollo 12. It contained two Teflon bags with the planned "selected sample" of 20 rocks and fine grained material. It was retained in "As Returned" condition by the Lunar Receiving Laboratory until 1977 and then transferred to the Smithsonian.