What useful inventions will probably never be used in everyday life?
The bath mouthpiece.
It is a real invention, patented in 1981.
It is the last possible resource for obtaining breathable air during a fire in hotels and homes when people cannot leave the room.
In fact, many people die of asphyxiation.
I would prefer this resource instead of dying .
Very bizarre, but it certainly could have saved many people's lives.