I have one of those on my Fuji. It seemed to be (to me at least) one of the most functional and ingenious little bits I've seen any bicycle. I thought it strange that it never became more widespread than it apparently did.
Regards,
John Barry
Mechanicsburg, PA, USA
Supposed to keep chain from whacking chainstay and damaging paint, that was
not gerffed-up installing the
cable guide.
Charlie Petry (older than most-not as old as some)
in Jennersville PA USA Planet Earth