From top to bottom in Rack 6 can be seen:

• The Vacuum Interface Assembly, which distributes vacuum to ALFE and others in the Spacelab.
• The Electronics Control Assembly, which receives signals from the computer to control the ALFE hardware.
• The Keyboard/Display Terminal for the microcomputer.
• The Bag-In-Box, housing the breathing bags. Attached to the front of the BIB is the Hypoxic Scrubber Assembly.
• The Gas Cylinder Assemblies, containing the tanks of gas which are dispensed by ALFE into the breathing bags for the various pulmonary function tests.
• The GASMAP, which analyzes gas concentrations in the air at the ALFE mouthpiece.
• The Microcomputer, which controls ALFE with special software.