The Headlamp (e17, E18, E21, E22) is made up of components including this Headlamp Assy which is the most expensive.
nine components are shown in this Gp125 1978 (c) (e01 E02 E04 E06 E13 E17 E18 E21 E22 E24 E30) Headlamp (e17, E18, E21, E22) exploded diagram.