situation the thermal contact between the second housing 2 and the first housing 1 can be realized in an end region of the first housing 1 facing to a light emergent side of the lighting module not shown i e in the upper part of the figure there is a stop portion 11 for the assembling part 22 the stop portion 11 extends radially inwardly starting from an inner wall of the first housing 1 so as to form a ring structure the assembling part 22 is sandwiched axially between the stop portion 11 and an end surface of an inner circumferential wall a 1 thus it can be ensured that the assembling part 22 is located in a fixed position in the first housing 1 so as to prevent the second housing 2 when influenced by an external force from stripping from the first housing 1 in the present embodiment the lamp holder 100 is configured as a cup with a cross section which is circular however it also can be taken into consideration that in a second embodiment not shown the lamp holder is configured as a cup with a square cross section or other rotationally symmetric cups besides in a third embodiment.