On this parts fiche the Rubber, Cushion is the most specified component.
A sample from the products for the Taillight (e,ed,f,g) include: Lens,taillight, Collar No Bracket, Cord Comp.,tail, Bulb (12v21w-5w).
The Cb750k7 Four England Taillight (e,ed,f,g) consists of sixteen pieces with the Taillight Unit being the most expensive.