The Screw is the lowest priced item on this Turn Sicnal Lamp (model X : E21) schematic.
Some items from this specific schematic: Cushion, Nut, Lens, Lens.
With all the components that make up the GS850G (E01 E02 E04 E17 E18 E21 E22 E24 E25 E26 E34 E39 TURN SICNAL LAMP (MODEL X : E21) assembly. The Screw is the most frequently specified with four applications.