Oxygen supply and return hose for the Apollo space suit, with connector panel.
The hose is covered with a Beta cloth sleeve. Over the sleeve is a protective Beta cloth cover to shield it during
testing and ground handling. This outer cover is removed before flight.
At the blue supply connector, the outer cover is lose enough to reveal a “C” on the inner sleeve. This
indicates it was for the Center astronaut.
The mechanism of the panel opens the supply valve when the hose is connected or when the lever is moved to the CABIN FLOW position. With the hose connected, moving the lever to the SUIT FULL FLOW position then opens the return valve.
Photos below show the hose connected to the panel, and a hose connected to the panel in the Apollo 11 spacecraft (NASM photo).