The lithium hydroxide canister was designed to maintain a pure-oxygen environment within the Apollo spacecraft by filtering out carbon dioxide, odors, and debris. The LiOH within the canister absorbed carbon dioxide, and carbon in the form of charcoal eliminated odors. The circulation within the spacecraft also carried debris to the canister, trapping it in the filter.
This filter was flown and deployed in the Command Module "Columbia" during the historic Apollo 11 lunar-landing mission in July 1969 and transferred to the Smithsonian in 1970.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.