Abstract: A fitting for a lighting fixture mountable in an aperture of a ceiling board, and wherein the ceiling board defines a first plane, includes a support device supporting the lighting fixture, and defining along a contour thereof a second plane substantially parallel with the first plane, a fixture-shift aiding device for shifting the lighting fixture between first and second stable positions along the support, so that the the plane of the lighting fixture may be positioned at first and second respective distances from the first plane of the ceiling, and a socket cover arranged to abut an upper portion of the lighting fixture. The support includes a tube member having on the interior thereof an inwardly projecting shoulder, a cylindrical cover slidable over the tube member, and a resilient device connecting the socket cover to the tube member.