The component with the lowest price in the F-13 AIR CLEANER - BATTERY schematic is the Washer,plain, 6mm.
Parts such as the F-13 Air Cleaner - Battery: Tube,vinyl, Bolt,hex 6x25, Fuse,10a,25mm, Suspension,winker are included in the Ct125 U.s.a F-13 Air Cleaner - Battery parts fiche.
In this schematic the "Nut,hex 6mm" is used most often.