The robot teleporter is a large machine about the size of Dr. Eggman in his Egg Mobile. It is mostly black with both ends of its 'shell' parts being silver. These 'shells' also appear to have yellow, black and red stripes, and are divided by three columns of electricity.
There is a dilapidated version of the machine placed in the present of the Rounds. It looks similar to the regular one, but all the colors are replaced by shades of blue and there's no electricity going through it.
Although its story purpose is debatable, the robot teleporter provides a very definite purpose in-game. In gameplay, it is placed in the past of all Rounds. Destroying the robot teleporters in one Zone will grant a good future for that Zone and destroy all badniks there. Destroying all the robot teleporters in the game, along with the Metal Sonic holograms, will earn the player the good ending for Sonic the Hedgehog CD.