E-Gate

An E-Gate is a tool used by Luigi in Luigi's Mansion: Dark Moon to reach places where he normally wouldn't be able to. The E-Gate functions as a portal, as soon as Luigi uses the Strobulb on the green circle on top of it. In pair, only one needs to be activated so that they work. The other does not have a green circle, and therefore cannot be activated.

This particular type of gate first appears in the Secret Mine, during the events of mission D-2 "Hit Rock Bottom", where Luigi will use them to his advantage to obtain items and get to various other places. The next and only other time they appear is in the Treacherous Mansion, where they will play a much bigger role. In fact, one time in the mansion, Luigi must use the E-Gates to transport various items to other rooms in order progress forward. There are six total E-Gates in the Treacherous Mansion, and all lead back to the Front Entrance, four on the first floor and two on the second floor: the far left E-Gate leads to the Dark Age Exhibit, the one next to that leads to the Ice Age Exhibit (that's also why it has snow around it), the far right E-Gate leads to the Jungle Exhibit (that's also why there're vines growing around it), and the last one leads to the Ancient Exhibit (that also has sand flowing out from it). On the top floor, the left E-Gate leads to the Space Exhibit, while the right can lead either to the Nautical Exhibit or the Study, depending on which way the large compass on the floor of the Nautical Exhibit is facing (north will lead to the Study, while south leads to the Nautical Exhibit).

Trivia

 * The green light on the top will follow Luigi's light. This can result in it clipping through the red ring.