This Intermatic K4223C thermal type photo control provides dusk-to-dawn lighting control of security lights, walkway lights, and flood lights and features a delay action, which prevents lights from switching off due to lightning or car headlights. This stem and swivel mounting photocell features a light level slide, which reads daylight watts between 3100 and 4150 and functions in temperatures from -40 degrees to 158 degrees Fahrenheit. With a standard 1/2-inch stem with 14 threads and 6-inch leads for safe and secure mounting, this photocell comes with a nut and a washer to complete installation, and also features a sonic-welded polycarbonate case and lens to seal out moisture, ensuring your unit is protected from the elements. With a dual-temperature compensating bi-metal and composite resistor to withstand temperature extremes, this photocell is a great choice for your photo control needs. The unit is California Title 24 compliant and works on 208-277 volt systems.