While wearing their spacesuits, Apollo astronauts wore urine collection devices underneath to collect waste. A tube like this would have connected to the urine collection device to then transfer urine to the spacecraft's systems for eventual venting into space. This tube was part of the equipment assigned to command module 014, a Block I version which was disassembled during the Apollo 1 fire investigation.
NASA transferred this urine transfer tube to the Smithsonian in 1974.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.