Amazon.com: Hyperkin 4-Port Controller Adapter for GameCube Compatible with Nintendo Switch/ Wii U/ PC : Video Games
GameCube Controller 4 Port Adapter by TTX Tech for Nintendo Switch and Wii U - Walmart.com
Gamecube Controller Adapter for Wii U - Solaris Japan
Confirmed: The Wii U GameCube Controller Adapter will not work on DDR, Active Life, or Cyberbike | Gaming.Fit
New Nintendo Wii U & Switch GameCube Controller Adapter Official Genuine | eBay
4-Port GameCube Controller Adapter for Switch Wii U PC Mac
GameCube Controller Adapter for Wii U, Nintendo Switch and PC USB by L
Wii U can use two GameCube controller adapters
Amazon.com: Y Team Controller Adapter for Gamecube, Compatible with Nintendo Switch, Super Smash Bros Switch Gamecube Adapter for WII U/PC with 4 Port : Video Games
Official Nintendo GameCube Controller Adapter Switch Wii Wiiu - Brand New | eBay
Amazon.com: Gamecube Controller Adapter for Switch/Switch OLED.Gamecube Adapter Compatible with PC Wii U.Adapter with 4 Ports 6 FT(1.8M) Cable Support Turbo and Vibration Features Super Smash Bros : Video Games
GameCube Controller Adapter for Wii U and PC USB Two ports
Nintendo GameCube controller adapter coming to Wii U for Smash Bros. - Polygon