in the late '70s. They featured a different shape to the bead seat, because some of the Europeans were still skeptical about tubeless tires on conventional rims, and in order to prevent the ignorant from trying to mount ordinary tires which weren't moulded for that type of bead seat, they made them in metric diameters which fell in between the time-honored inch sizes. A lot of these were sold on early Fox-bodied Mustangs, starting about 1978, and on BMWs in the early '80s, but by now almost everyone has replaced them with conventional rims, and Michelin has not upgraded the design of the tires they market in these sizes for almost 20 years.

In other words, they're very obsolete and not really desireable.