The 480 V 50/60 Hz. 7200 Watt "T" Locking Type The K4500 Series Photo Controls feature locking-type mounting and thermal-type controls that are equipped with standard 3-prong locking-type plug connections. Thermal-type photo controls provide dusk-to-dawn lighting control and provide delay action, which eliminates loads switching OFF due to car headlights, and lightning. The theramal-type controls feature a cadmium sulfide photocell and sonic welded polycarbonate case and lens to seal out moisture. The design utilizes a dual temperature compensating bimental and composite resistor for reliable long life operation over ambient temperature extremes.