The Communications Cable Assembly (or Electrical Umbilical Assembly) was used by astronauts during the Apollo missions to power and connect communications and monitoring devices contained in their spacesuits or other garments to spacecraft systems. The cable provides the path for audio signals to and from the communications carrier headphone device worn by the astronauts. It also provides the necessary path to provide power to the carrier microphone and to the biomedical monitoring equipment. Output data signals from the biomedical sensors are also carried by the communications cable.

Control functions were accomplished with the communications cable control head attached to the cable, a unit that contains a self-centering rocker switch which, when depressed on one side or the other, initiates specific functions.

This container was for the spare control head stowed in locker L2 during the Apollo 11 mission in July 1969. It was transferred to the Smithsonian in 1970.