GAMECUBE CONTROLLER ADAPTER FOR SWITCH (ALSO WII U / PC)
Y Team Controller Adapter for Gamecube, Compatible with Nintendo Switch, Super Smash Bros Switch Gamecube Adapter for WII U, PC, 4 Port ,Black, W046 - Walmart.com
Wii U's GameCube controller will support more than just Smash Bros. [updated] | VentureBeat
Gamecube Controller Adapter for Switch Gamecube Adapter Wii U and PC, Super Smash Bros Choice Support Four Gamecube Controller and 70IN Long Cable - Newegg.com
Amazon.com: Mayflash GameCube Controller Adapter for Wii & Wii U (Dual Pack), White : Video Games
GameCube Controller Adapter for Wii U, Nintendo Switch and PC USB by L