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Amazon.com: pdobq Gamecube Controller Adapter for Nintendo Switch / WII U / PC. Super Smash Bros Switch Gamecube Adapter. 4 in 1 Plug and Play Game Cube Adapter : Video Games
MAYFLASH 4 Ports GameCube Controller Adapter for Wii U & PC USB - Newegg.com
2 In 1 Controller Adapter Converter For W ii U PC For GameCube to Nintendo WiiU Nintend Switch For NS 4 Ports and No Need Driver|Replacement Parts & Accessories| - AliExpress
Mayflash GameCube Controller Adapter for Wii U and PC USB (4 Port) - Walmart.com
Here's how to get Wii U's GameCube Controller Adapter working on Windows | VentureBeat