Rotor

The Rotor is an object in Luigi's Mansion: Dark Moon that appears in the Old Clockworks Mansion. It is needed to open the Clock Tower Gate door. Luigi first sees it in the grasp of a Strong Scarer who is trying to hide it in C-5: Piece at Last. After finding the Toad Maintenance worker and capturing all the Ghosts, Luigi gets the Rotor and can use it to open the Clock Tower Gate Door in C-Boss: Showtime. Other rotors appear in several other mansions however this is the only one that is classified as a "Rotor" and it is also the only one that isn't already attached.