They usually have them at airports or at the entrance to large buildings. They are big enough to comfortably fit maybe ten people in each section.
I see them on TV and I wonder, what would happen if someone got their arm caught in one? Would that be an instant breakage, or even dis-arm of the arm?!
When I’ve had occasion to actually use one I’ve felt a little unsafe shuffling myself along with everyone else as the thing revolves.
How safe are they? (I’d feel much safer pushing open a conventional spring-shut glass door)