They're no longer available from Honda. Allegedly these were used in all of the CB750 K bikes from late 1969 to 1978, the Hondamatic 750, the DOHC 750 K and L from 79 to 82, and the SOHC CB650 K and Nighthawk. If you've got a rear wheel from any of these bikes taking up space in your life I'll take it off your hands.