Labyrinth seal is a mechanical seal that fits around a shaft to prevent the leakage of oil or other fluids. It is composed of many straight threads that press tightly inside another shaft, or stationary hole, so that the fluid has to pass through a long and difficult path to escape. Labyrinth seals on rotating shafts provide non-contact sealing action by controlling the passage of fluid through a variety of chambers by centrifugal motion, as well as by the formation of controlled fluid vortices. If the labyrinth chambers are correctly designed, any liquid that has escaped the main chamber, becomes entrapped in a labyrinth chamber, where it is forced into a vortex-like motion. Turbines use labyrinth seals due to the lack of friction, which is necessary for high rotational speeds. They are also found on pistons, which use them to store oil and seal against combustion explosions, as well as on other non-rotating shafts. It is an effective barrier against water and other contaminants that destroy bearings.