MTD

The MDT, or the Teleporter, is an interactive object created and found in Der Riese, Kino der Toten, "Five", Moon, and Dead Ops Arcade when the players need to enter a different area. They were being built by Dr. Maxis and Richtofen along with their secret weapon, the Wunderwaffe DG-2. However, they were having many problems with the teleporters even at the point when Maxis and his daughter were sent to Griffen Base. Somehow these problems were fixed by the time Richtofen and the others returned.

Der Riese
The teleporters in Der Riese transport players from the teleporters A, B or C to the mainframe (spawn location). The teleporters can only be used by activating the power (the switch is located in the Mystery Box spawning room) and then linking them to the mainframe. One player must go to the teleporter to activate it and another player can link it to the mainframe. To link a teleport to the mainframe, the player must use the action button over the mainframe pad. To teleport, the player must stand in the teleporter, and press the action button. The teleporter costs 1500 points per teleport, and may sometimes give a random power-up or summon Hellhounds to attack.

Kino der Toten
In Kino der Toten, the teleporter is available after the power is turned on and is free to use. To link the teleporter, the player has to press the action button in the teleporter, there being no timer to link it to the mainframe in the lobby (spawn location). After this is done, the player will be able to teleport to an upper balcony with the Pack-a-Punch machine, and then usually teleports the player to a random room where power ups and/or film reels are occasionally placed, and then back to the mainframe. However, it can sometimes just teleport players back to the Mainframe.

"Five"
In "Five", the teleporters are free to use and appear after the power is turned on. Unlike the other teleporters, they appear to be balls of red electricity and teleport the player to another teleporter, instead of the mainframe. Zombies can also use these teleporters once the power is turned on. The Pentagon Thief also spawns from one of these. It is interesting to note that the teleporters on this map appear to be of US design, as they feature the US army logo on the base and are differently colored. This is because these teleporters were created by using the Nazi teleporters as examples, as indicated by intel and the fact that an old mainframe can be seen behind a window. This new form may seem like a blessing, though it is much more of a hazard, as it cannot be used as a short relief from zombies, as any mass chasing the player will soon teleport after them. Plus, all teleporters only teleport the player to a random location, meaning the player cannot rely on them to get them to where they want to go. Unlike the teleporters in other maps, the ones in "Five" can only let one person teleport at a time.

Moon
In Moon, a teleporter is used to get from the moon base to Area 51. If the player uses the Hacker, they will be trapped in Area 51. The teleporter will only activate in Moon when all of the players are on it. In Area 51, the teleporter will activate either when all of the players are on it or after one player reaches it and the timer (indicated by the alarm) ends. The teleporter is always free to use.

Time Travel
According to Richtofen, the MDT is capable of time travel. It would appear this happens when it is overloaded with Element 115. The original characters time travel as a result of one of the group obtaining a Wunderwaffe DG-2 (as evidenced in a radio in the Black Ops version of Shi No Numa) and using the MDT, overloading it with the 115 in the Wunderwaffe and sending the group into the future. This also apparently causes the Wunderwaffe to be drained of it's power, which would explain why it can't be found in Kino der Toten or Ascension. Its unknown how the characters were able to time travel from the cosmodrome in Ascension as no MDTs are present there, but it is known that somehow the characters accessed an MDT which was overloaded due to the high amount of Element 115 used in the Kassimir Mechanism, and sent them to an abandoned Siberian lighthouse where they were trapped. After the MDT was repaired, it teleported to Shangri-La, but strangely appears to not cause the constant time travel the four go through during the Eclipse.

Achievements/trophies

 * Der Electrician - Link all of the teleporters before round 7.
 * Frequent Flyer - Use the teleporter 8 times.

Trivia

 * The teleporters in Nazi Zombies are a version of Die Glocke (The Bell), a device that was made during World War II in a secret test facility in Poland called Der Riese. Die Glocke is the subject of many conspiracy theories; some claim that it was an anti-gravity device, and other sources say that it was intended for teleportation and/or time travel, as it is used in the game.
 * Any Zombie or Hellhound entering the MDT in Kino der Toten or Der Riese when it is activated will be instantly killed. Zombies will not die and can in fact use the teleporters in "Five" as they are different than the other maps' teleporters.
 * After the teleporters in Der Riese are used several times, it will not spawn power-ups and Samantha will yell various sentences, such as "No treats for you!" after use, and after even heavier use, it will start to spawn packs of Hellhounds.
 * Sometimes, if the player is in third person viewing mode while spectating and the person the player is spectating teleports, they will see the person in the vortex room the player gets sent to when teleporting.
 * If a player is downed and somebody turns on the teleporter while the player is inside it, the player will still be teleported.
 * Near all the teleporters in Der Riese, either underground or lying besides it, there are three wooden signs, one by each teleporter. All of these have three letters on them, which read "ENG", "GER" and "FRA". This is shortened words for the countries England, Germany and France. This suggests that there are other teleporters in different countries, but those may be out of commission since players can only teleport inside Der Riese.
 * When the teleporter in Kino der Toten is used, a small red 0, will come up next to the players score, as if they have bought something that cost 0 points.
 * On "Five", if two players go through a teleporter at the same time, both players will get downed. A laugh will be heard if this occurs, similar to the laugh from getting a Teddy Bear from the Mystery Box.
 * One of the pictures seen in the Der Riese teleporter is concept art for a Gas Zombie, which wasn't actually seen until Kino der Toten.
 * In "Five", once the players have every DEFCON switch pulled, all teleporters will have an image of the Pack-a-Punch Machine in them, indicating that they all lead to the Pack-a-Punch Machine. This also happens if the players get a Bonfire Sale.
 * In Ascension, the Gersch Device acts as a teleporter by teleporting the player to any part of the map when the player jumps into an active Gersch Device.
 * In their every appearance, they are essential to reaching the Pack-a-Punch Machine, Having to link all three to the mainframe to lower the door for it in Der Riese, having to use the Teleporter to get to the Pack-a-Punch Machine Room in Kino der Toten, Having to lower the DEFCON Switches to get all the Teleporters to go to the Pack-a-Punch Machine in Five, and Having to step on it to reach the Receiving Area in Moon.