Rumble Pak
Using this accessory, vibrations that occur when playing the game (e.g. when bumping into obstacles) are transferred to the Nintendo DS so that you can experience the game in a very realistic manner.
The Rumble Pak is black and looks like a Game Boy Advance game. It is inserted into the Game Boy Advance module slot (SLOT-2) on the Nintendo DS and is only supported by games that have been especially designed with this function.
The Nintendo DS Rumble Pak is also compatible with the Nintendo DS Lite.