The pressure on a suction cup as exerted by collisions of gas molecules holds the suction cup in contact with the surface.
One cup suction lifter.
A suction cup, also known as a sucker, is an object that uses the negative fluid pressure of air or water to adhere to nonporous surfaces, creating a partial vacuum.[1]
Suction cups are peripherial traits of some animals such as octopuses and squids, and have been reproduced artificially for numerous purposes.[2]