Abstract: Disclosed are rotatable electrical connector units and adjustable lighting devices incorporating these units. The rotatable electrical connector unit in accordance with the invention comprises a shaft which is at least partially hollow and at least three electrically insulating discs mounted transversely on the shaft, each of the discs carrying at least one electrical contact ring. The electrical contact rings are arranged on the discs such that there are two pairs of electrical contact rings, each pair separated from each other, and such that the contact rings of each pair are in slidable electrical contact with each other. The unit further includes a housing about the shaft and the discs, a portion of the housing engaging at least one of the discs such that when the housing portion is rotated relative to the shaft, the engaged disc is caused to rotate about the shaft. At least four electrical conductors extend from the unit, each electrical conductor attached to a different contact ring.