This type of LiOH canister was made famous by the Apollo 13 mission, where the astronauts
were forced to move into the Lunar Module (LM) for most of the flight. Having exhausted the capacity of the LM LiOH canisters, the Command Module (CM) canisters were needed. However, the
square CM canisters did not fit into the round LM openings. So a workaround was devised using the CM canisters with hoses, tape, and other items.