The most reasonably priced component used on the Gs650g 1981 (x) (e01 E02 E04 E06 E16 E18 E21 E22 E24 E39) Turn Signal Lamp (e2, E4) is the Screw.
This part-list fiche shows all the components that make up the Gs650g 1981 (x) (e01 E02 E04 E06 E16 E18 E21 E22 E24 E39) Turn Signal Lamp (e2, E4) .
Some items from this specific schematic: Gasket (nas), Rim, Washer (10.5x30x2.3), Lens.