This propellant quantity indicator was installed on the command pilot's control panel in the Gemini capsule. It displayed the hypergolic propellant level in storage tanks. The propellant was used by the sixteen engines of the orbital attitude and maneuver system. This artifact was never flown in space. Western Instruments made the indicator and NASA transferred it to NASM in 1972.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.