A sample from the products for the Rear Combination Lamp (e2, E4, E21, E26) include: Screw, Nut 6mm, Bulb, Bulb(12v21/5w).
On this parts fiche the Screw is the most specified component.
The most reasonably priced component used on the Gsx250s 1982 (z) General Export (e01) Rear Combination Lamp (e2, E4, E21, E26) is the Bulb(12v21/5w).