The Time Turner from Harry Potter and the Prisoner of Azkaban

Best used sparingly, the time turner is a magical device that allows the person wearing it to travel back in time a few hours with just a few turns of an hourglass. In the Harry Potter franchise’s third film, Hermione (Emma Watson) secretly uses it to take extra classes at Hogwarts, but when her pals Harry (Daniel Radcliffe) and Ron (Rupert Grint) find themselves in deep trouble, she shares its power with them to help save the day.