German car hand lamp trouble light

Vintage German car hand lamp trouble light in good condition. I tested the light with 6V and it is working. I did not check if the bulb inside is 6V or 12V but it can be used with both sorts of bulbs. The lamp is 16 cm length, the bulb cover lens is stamped with "GERMANY, MAX 18W". The yellow cable is the first and original and possible the plug too. It is good old quality. The last picture shows the hand lamp in an old German part catalog.