In this schematic the "Cushion, Tank" is used most often.
Parts such as the F-26: Grommet,wire Cord, Cushion, Tank, Pin Cotter 2.5mm, Cap, Tool Box are included in the Cb450k3 Japan F-26 parts fiche.
The Cb450k3 Japan F-26 consists of six pieces with the Fender Rear being the most expensive.