A number of gates of Chozo design are present in the Vault room of the Chozo Ruins. They guard a Missile Expansion and require a number of Morph Ball Slots to be activated to lower them. The gates are black and constructed of metal, and depict shapes similar to the Chozo Artifacts. The gate at the other end of the room that leads to the Main Plaza contains three Morph Ball Slots within its workings. The Slots appear differently from others in Metroid Prime. They are connected and situated on an ascending curve; the second and third Slots require a Bomb Jump, Double Bomb Jump or a Spring Bomb Jump (Wii versions only) to reach. The first and second Slots are also covered by grating which can be removed through Bombs. Once a Slot is used, a lock beside it will move into place, and the blue li