Photocell 1800W 120V Rated. The K4121C has a mounting arm with a 1/2 inch knock out mount. Slider for adjusting light levels. The K4100 & K4400 Series Photocontrols feature stem mounting, thermal-type, controls with single and multi-voltage models. Thermal-type photocontrols provide dusk-to-dawn lighting control and a delay action, which eliminates loads switching OFF due to carheadlights, and lightning. The thermal-type controls feature a cadmium sulfide photocell and a sonic-welded polycarbonate case and lens to seal out moisture. The design utilizes a dual temperature compensatingbimetal and composite resistor for reliable long life operation over ambient temperature extremes. These models are California Title 24 compliant.