Acoustic Tone Booster, Apollo 11

A special stowable device was provided in the Apollo Command Module that could be connected to the spacecraft caution and warning system and mounted on either side of the spacecraft. Its purpose was to allow all three astronauts to sleep simultaneously with their headsets removed and warn them with a loud acoustic signal if, while asleep, an event occurred that required their attention.Consisting of a power plug, a tone booster, and a photosensitive device to trigger the tone whenever the spacecraft Master Alarm lamp became illuminated, this unit was flown on the Apollo 11 Command Module during its historic mission. It was transferred to the Smithsonian in 1970.