Abstract: A lighting device is disclosed which includes a vertical support, an elongate horizontal arm connected to the vertical support via a connector, and a light source mounted on the arm. The elongate arm consists of, or consists essentially of, an elongate heat sink, and the lighting device further comprises an elongate heat pipe positioned within the heat sink and in thermal contact with the light source. The elongate arm and the vertical support include elongate channels formed along at least a portion of their lengths, and the connector comprises a sheet structure having a plurality of wheels rotatably mounted thereon, wherein the wheels are arranged to ride along the elongate channels, such that the elongate arm can slide relative to the vertical support in directions both parallel to and perpendicular to the length of the arm. The elongate arm and connector are connected to a counterweight via a flat, flexible power cable arranged around first and second pulley wheels.