That’s Gary Carlton’s chassis line. He was one of the top shifter drivers in the US not that long ago, but now I think he primarily focuses on promoting this chassis line and running his own race team. I’ve linked a thread from a few years ago - it sounds like he worked with TB Kart in developing it, so they are probably very similar and share most major components. Unfortunately I’ve never driven either kart so I wouldn’t be able to help with any driving comparisons, but maybe someone else can.