What is a rubber sucker? How does it work? State any one use of a rubber sucker.

Rubber sucker a device used in toys, sunlight blocker - suction cups, suction clamps and various other places where "sticking" is required for temporary period and when you don't want to use glue.

The principle on which Rubber suckers work : When the sucker is pressed against the surface, it squeeze out the air that is behind it. The atmospheric pressure on the outside of the sucker holds its rim firmly against the smooth surface.