A car headlamp has a peripheral wall (8) at the rear with which the lamp socket cover(13) engages. There are several slits around one edge of the wall and protruding lips on the rear wall edge. These engage with claws on the socket cover, forming a watertight seal. The reflector has two sections (12a,12b) with different focal points. The inner section has a focal point that falls within an imaginary circle through the slits. The socket cover has ventilation holes. The ventilation is assisted by the heat convection from the bulb. The cover also has a sleeve which grips the periphery of the bulb base to give a watertight seal.
