On at dusk, Off at dawn photocell. Operates in any position when used with PAR38 floodlight or spotlight. Also works with standard light bulbs. Fits most outdoor fixtures. Ideally suited for patio and driveway protection. 120V AC, 150-watt capacity. Incandescent, CFL (compact fluorescent), LED (light emitting diode), and halogen compatible. UL (Underwriter's Laboratories) listed.