Amazon.com: Retro-Bit Official Sega Saturn 2.4 GHz Wireless Controller 8-Button Arcade Pad for Sega Saturn, Sega Genesis Mini, Switch, PS3, PC, Mac - Includes 2 Receivers & Storage Case (Slate Gray) :
PSA: If you're buying 3rd party Saturn controllers, get these! : r/SegaSaturn
Using The Shield Gamepad Mapper - Nvidia's Shield Revisited: Console Mode, Streaming, And More