Parts such as the Carrier Rr: Carrier Rr, Bolt,special Flan, Nut, Flange, 8mm are included in the Cb250 2000 (y) Portugal Carrier Rr parts fiche.
The Nut, Flange, 8mm is the cheapest item from this partsfiche.
The Honda CARRIER RR has three products enlisted in the schematic.