Game Link Cable Adapter / Converter Connector
MGB-004 · Nintendo
Why
There’s no units produced with a source and not enough listings. We don’t make things up.The Game Link Cable, also known as Video Link in early versions, is an accessory for the Game Boy line of handheld consoles. Introduced in 1989 alongside the original Game Boy, it was revised over four generations with varying degrees of backward compatibility. The cable enables data transfer and multiplayer gaming between up to four devices, supporting head-to-head competition, cooperative play, item exchanges, and unlockable features, depending on the game. The cable could also connect the console to external peripherals, most notably the Game Boy Printer. The port on Game Boy consoles is labeled "EXT" for Extension connector.
For now, in English only. Source: Wikipedia, CC BY-SA 4.0How to tell them apart
Small plug adapter: 2nd-gen plug on one side, 1st-gen socket on the other.
Details from sources
Lets a DMG-04/04A cable plug into Pocket/Light/Color, and into GBA/SP when running GB/GBC games.
Data source: nintendo.co.jp
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