a 24" wheel, double width with 10ga spokes. Turns out it was a custom build for the owner's whizzer. Freaking awesome as well, I might add. Turns out the owner is a massive whizzer nut, and so is his family. They have family&friends rides every other month or so.
edit: forgot the "for sale" part. Oddest for sale has to be an original set of 1970s 10-sp brake levers. I couldnt believe my eyes when I saw them...almost bought them too, just for the sake of saying I have NOS brake levers that are older than I am