This tank was part of the ApoIIo/Skylab Electrical Power System, Cryogenic Storage Subsystem and was designed to provide oxygen to the Apollo fuel cells for electrical power generation, as well as for the crew to breath. It was designed for mounting in the Service Module. Manufactured by Beech Aircraft in 1971/1972, this unit was originally installed in CSM 116 (Skylab 2) but removed and replaced prior to flight due to a suspected leak. The tank is configured as modified after the Apollo 13 incident (the fluid stirring fans are removed, a three element heater-instead of two-is installed, it contains a stainless steel quanitity probe, and has an added heater and temperature sensor).
The tank was transferred from NASA to the Smithsonian in 2004.