We don't currently have an official adapter available for the Nintendo Switch. However, Nintendo recently released firmware update 4.0 that enables GameCube controllers to work on the Switch when used with their official GameCube-Wii U adapter or with 3rd-party ones like this. Our 5in1 adapter (GameCube connection) will allow the X-Arcade controllers to work on the switch with that adapter. To enable it, press L & R simultaneously when pairing controllers and use the analog/DPad modifier to get the joystick to work. The Start button acts as the + button.
Keep in mind this will only work with games that have GameCube controller support. Also, it may not work if the game absolutely requires the right bumper shoulder or - (minus) to work since GameCube controllers lack those buttons. There is also no Home button, so you will need to use another controller when you need to go Home..
We can also confirm that this Brook GameCube-Switch adapter does NOT work with our adapters.