Controller Extension Cable.
The Controller Extension Cable for the Sega Saturn is a third-party accessory manufactured by Performance.
Essentially, all the Controller Extension Cable does is extend the lead of any Saturn contoller by six feet (≈ 1.82 metres). It works for any peripheral which uses these ports, bar those which require both controller ports at once (such as the Saturn Infrared Control Pad). Theoretically this would still function properly if a second extension cable was introduced, though it would largely defeat the purpose of wireless controllers.