Retro-Bit Legacy 16 Wireless 2.4GHz Controller for SNES, Switch, PC, MacOS, RetroPie, Raspberry Pi and Other USB Devices (Gray Classic) - Walmart.com
Legacy16 Wired USB Controller - RetroBit - Stone Age Gamer
LegacyGC - The next stage of your legacy has arrived!
Retro-Bit Prism HD Adapter Review — GameTyrant
Amazon.com: Retro-Bit Prism HDMI Adapter for GameCube - AV to HDMI Converter/Upscaler for 1080P Support : Everything Else
Amazon.com: Retro-Bit Legacy GC Wired Controller - for Gamecube & Wii - Indigo : Video Games
Tribute64 V2 2.4G Wireless Controller for N64/Switch/USB - Red
Here are some usb controllers I've been experimenting with sm64- switch pro controller w/ notched faceplate, retro bit usb n64 controller, switch brawler controller : r/speedrun