Examples of practical effects include tripping and falling down, high jumps, extreme sporting moves, acrobatics and high diving, spins, gainer falls, “suicide backflips,” and other martial arts stunts.[citation needed] Stunt airbags (or “stunt mats”), large deep airbags that may be the size of a small swimming pool, are typically used by professional stunt performers to cushion their landings from staged falls from heights.