1945 GEC-Osram 5L/2343 (12 V 350 W)

This special incandescent lamp was made during the second World War for an application in aviation, more specifically in landing lights. In order to ensure an efficient and accurate coupling with projector's optics, this 5L/2343 is provided with a prefocus P40s end cap and a very compact 350 W coiled filament designed for an operation on 12-V circuits. Such construction also makes the lamp very resistant towards shocks and vibrations. In order to withstand its high thermal load (the bulb is 8-cm in diameter only), the lamp is made of hard borosilicate glass and the lead wires are folded so as to limit the amount of heat conducted from the filament to the pinched seal. A more direct connection would lead to seal failure. The thick filament consists of two coiled sections placed very close together so as to form a very compact source of light, crucial for the projection of a precisely shaped beam of light.