This is the adapter for GameCube controllers that was included with the Wii U version of Super Smash Bros. It is not a compatible product or a later version. You can also use it without any problems with Super Smash Bros. Ultimate for Switch. However, I have already disposed of Super Smash Bros. for Wii U separately, so there is no box or instruction manual. Please be aware of this. I originally played with a GameCube controller, but I switched to the Pro Controller and haven't used this since, so I am selling it. It has a considerable amount of use, but there is no noticeable damage. The stains in the photos are from the paint of the controller transferring onto it. (I think it was caused during travel, as I took it with me on business trips, etc.)