Rumble Pak

The Rumble Pak (Japanese: 振動パック, Hepburn: (Shindō Pakku^?) is a removable device from Nintendo which provides force feedback while playing video games. Games that support the Rumble Pak cause it to vibrate in select situations, such as when firing a weapon or receiving damage, to immerse the player in the game. Versions of the Rumble Pak are available for the Nintendo 64, the Nintendo DS, and the Nintendo DS Lite. A select few Game Boy Color and Game Boy Advance games use a similar technology built into the game cartridge. The use of external Rumble Paks, since their introduction, is rare today, mainly because the force feedback vibration that they provide has become a built-in standard feature in almost every home video game console controller since.

The original Rumble Pak, designed for the Nintendo 64 controller, was released in April 1997 in Japan, July 1997 in North America, and October 1997 in Europe. It requires two AAA batteries and is inserted into the controller's memory cartridge slot, which prevents simultaneous use of the Controller Pak. This usually has little impact, as Nintendo 64 games are cartridge based and have the ability to store saved data in the cartridge, but for games that support the Controller Pak, it is possible to switch between accessories at certain points, a method known as "hot swapping".

The Rumble Pak was introduced bundled with the game Star Fox 64 (known as Lylat Wars in the PAL region) and made available as a separate purchase two months later. Rumble Pak support soon became a standard for N64 games. Launch titles Wave Race 64 and Super Mario 64 were re-released in Japan in July 1997 with Rumble Pak support.

...
Wikipedia