just FYI, the name is just Thunder Burt
A bit of an successor for the Furious Fred and combing best of Furious Fred and Racing Ralph.
It was only for a short period of time produced. I had one and liked it, but i haven't felt any advantages compared to the in my opinion great Furious Fred.
Those are also rarely available in good condition in 26", but maybe a recommendation to broaden your search criteria to get more results and feedback here.