It's not the only one around - a few others, all from China as far as I can see. Obviously the bearing size must be quite small - something like a 30x37x4 - but there are 2 each side. i am also concerned about the thickness of the notched lip - would this distort the chainline too much?
Specifically I am thinking about it for my YT Jeffsy, having accepted that whatever BB bearing setup one uses in typical UK winter usage one season is about the limit, although, that said, I got 2 winters out of the OEM RF setup.