Amazon.com: 8Bitdo Gbros. Wireless Adapter for Nintendo Switch (Works with Wired GameCube & Classic Edition Controllers) - Nintendo Switch : Everything Else
Hardware Review: 8BitDo GBros. Adapter - Use Your GameCube Pad Wirelessly With Smash Bros. Ultimate | Nintendo Life
8Bitdo Gbros. Wireless Adapter for Nintend Switch for GameCube for NES/for SNES/for Wii Classic controller|Replacement Parts & Accessories| - AliExpress
GBros. Adapter | 8BitDo
8Bitdo Gbros Wireless Adapter for Nintendo Switch For NES SNES 6922621500858 | eBay