Photoelectric eye with swivel adjustment. Ideal for darkness activated automatic control of night lighting. Use on porch lights, garden lights, post lanterns, barn lights, loading dock lights, outdoor signs, and more. Durable weatherproof construction. Built in time delay prevents operation triggered by auto headlights or other temporary light flashes. 2.93 In. W. x 4.75 In. L. x 0.21 In. D.